Abstract: The magnesium complexes of cyclic hydrocarbons containing conjugated dienes, such as 1,2-dimethylenecycloalkanes, and 1,3-butadienes, are readily prepared in high yields using highly reactive magnesium. Reactions of these (2-butene-1,4 diyl)magnesium reagents with electrophiles such as dibromoalkanes, alkylditosylates, alkylditriflates, bromoalkylnitriles, esters, or amides serve as a convenient method for synthesizing carbocyclic systems. Significantly, carbocycles prepared by this method contain functional groups such as the exocyclic double bond or a keto group in one of the rings which could be used for further elaboration of these molecules. Furthermore, fused bicyclic systems containing a substituted five-membered ring can be conveniently prepared at high temperatures by the reactions of (2-butene-1,4-diyl)magnesium complexes with carboxylic esters or acid halides whereas low temperatures lead to regioselective synthesis of .beta.,.gamma.-unsaturated ketones. Additionally, .gamma.

Abstract: A mesomorphic compound of the formula (I) according to claim 1 characterized by having at least one cyclic group selected from .beta. class including, e.g., thiazole-2,5-diyl, benzoxazole-2,5-diyl, indan-2,5-diyl, and quinoxaline-2,6-diyl and also having a linkage of Y.sup.1 (CH.sub.2).sub.m Y.sup.2, where Y.sup.1 and Y.sup.2 are --CH.sub.2 --, --O--, --COO-- or --OCO-- and m is 1-16, is suitable as a component for a liquid crystal composition providing improved response characteristics. A liquid crystal device is constituted by disposing the liquid crystal composition between a pair of substrates. The liquid crystal device is used as a display panel constituting a liquid crystal apparatus providing good display characteristics.

Abstract: Compounds having the formula I: ##STR1## are inhibitors of leukotriene biosynthesis. These compounds are useful as anti-asthmatic, anti-allergic, anti-inflammatory, and cytoprotective agents. They are also useful in treating angina, cerebral spasm, glomerular nephritis, hepatitis, endotoxemia, uveitis, and allograft rejection and in preventing the formation of atherosclerotic plaques.

Abstract: Compounds useful as antihypertensive agents and useful as antiviral agents against DNA-containing viruses, such as herpes group viruses, are disclosed. The compounds are represented by Formula 1.0: ##STR1## and their pharmaceutically acceptable salts and solvates. Pharmaceutical compositions containing compounds represented by Formula 1.0 are disclosed. Methods of treating a viral infection using compounds represented by Formula 1.0 are disclosed.Also disclosed are methods of treating hypertension using compounds of Formula 1.0 wherein R is selected from the group consisting of H, halogen and --C(O)OR.sup.6 ; and R.sup.1 is selected from the group consisting of --OR.sup.14, --O(CH.sub.2).sub.a C(H).sub.3-i Z.sub.i and --O(CH.sub.2).sub.h N(R.sup.15).sub.2.

Abstract: The present invention is concerned with antiretroviral (e.g. anti HIV-1) compounds having the formula ##STR1## Pharmaceutical compositions containing said compounds of formula (I-a) or (I-b), and processes of preparing said compounds and compositions.

Abstract: Compounds of the formula ##STR1## where R.sub.1 and R.sub.2 are hydrogen, lower alkyl of 1-6 carbons, or halogen; R.sub.3 is hydrogen, lower alkyl of 1-6 carbons, halogen, OR.sub.11, SR.sub.11, OCOR.sub.11, SCOR.sub.11, NH.sub.2, NHR.sub.11, N(R.sub.11).sub.2, NHCOR.sub.11 or NR.sub.11 COR.sub.11 ; X is O, S or NR' where R' is hydrogen or lower alkyl of 1-6 carbons; Y is phenyl or a heteroaryl group selected from a group consisting of pyridyl, thienyl, furyl, pyridazinyl, pyrimidinyl, pyrazinyl, thiazolyl and oxazolyl; A is (CH.sub.2).sub.n where n is 0-5, lower branched chain alkyl having 3-6 carbons, cycloalkyl having 3-6 carbons, alkenyl having 2-6 carbons and 1 or 2 double bonds, alkynyl having 2-6 carbons and 1 or 2 triple bonds; B is hydrogen, COOH or a pharmaceutically acceptable salt thereof, COOR.sub.8, CONR.sub.9 R.sub.10, --CH.sub.2 OH, CH.sub.2 OR.sub.11, CH.sub.2 OCOR.sub.11, CHO, CH(OR.sub.12).sub.2, CHOR.sub.13 O, --COR.sub.7, CR.sub.7 (OR.sub. 12).sub.2, or CR.sub.7 OR.sub.13 O, where R.sub.

Abstract: Compounds useful as antiviral agents against DNA-containing viruses, such as herpes group viruses, are disclosed. The compounds are represented by Formula 1.0: ##STR1## and their pharmaceutically acceptable salts and solvates; wherein:(A) X is selected from the group consisting of N--R.sup.3, O, S, and C(R.sup.3).sub.2 ;(B) R.sup.3 is selected from H and a range of substituents;(C) R.sup.1 is an etherifying or esterifying group;(D) R.sup.2 is selected from a range of substituents;(E) m is 0 or an integer from 1 to 4; and(F) R.sup.4 and R.sup.5 are the same and are selected from alkyl and acyl groups;together with the pharmaceutically acceptable salts of the compounds of Formula 1.0 that are acidic or basic.Pharmaceutical compositions containing compounds represented by Formula 1.0 are disclosed. Also disclosed are methods of treating a viral infection using compounds represented by Formula 1.0.

Abstract: Compounds useful as antiviral agents against DNA-containing viruses, such as herpes group viruses, are disclosed. The compounds are are represented by compounds of Formula 1.0: ##STR1## and their pharmaceutically acceptable salts and solvates. Pharmaceutical compositions containing compounds represented by Formula 1.0 and methods of treating a viral infection using compounds represented by Formula 1.0 are disclosed.Also disclosed are compounds useful as antihypertensive agents and methods of treating hypertension using such compounds. The antihypertensive agents are compounds represented by Formula 1.0 wherein R.sup.4 is selected from the group consisting of alkyl and aminoalkyl. Preferably R.sup.1 is H.

Abstract: This invention relates to a novel class of heterocyclic compounds useful for selectively inhibiting elastase, selectively inhibiting chymotrypsin-like enzymes, selectively inhibiting trypsin-like enzymes, or for generally inhibiting serine proteases of all classes.

Abstract: Fluorescent reagents possessing an activated phosphate for the convenient covalent coupling to the 5'-hydroxyl of oligonucleotides. A class of 5'-fluorescence-tagged oligonucleptides is also disclosed.

Abstract: Methods of treating chronic arthritis and osteoporosis which utilize both known and novel compounds which would fall under the general formula:(HO)p--A--[--OS(O).sub.2 NR.sup.1 R.sup.2 ].sub.zwherein A encompasses a wide range of values including but not limited to aryl, loweralkyl, cycloalkyl, and carbohydrates including sucrose and fructose; p is equal to the number of unreacted hydroxy groups contained on the molecule and may be zero; z is the number of --OS(O).sub.2 NR.sup.1 R.sup.2 groups and is always at least one; R.sup.1 and R.sup.2 are selected from hydrogen, loweralkyl, carboxy and the like; a novel process for preparing the compounds is provided wherein an appropriate sulfamic acid aryl ester is reacted with a hydroxy substituted A radical which may or may not contain thereon protected carboxyl, amino or hydroxy substituents, in an aprotic solvent containing a tertiary amine base. Pharmaceutical compositions for the treatment of chronic arthritis and osteoporosis are also provided.

Abstract: Seco-mevinic acid derivatives are provided which have the structure ##STR1## including all stereoisomers thereof, wherein Z is ##STR2## R is H, alkali metal or lower alkyl, R.sup.1 is H, lower alkyl, aryl, lower alkoxy, cycloalkyl, heteroaryl, aralkyl, heteroaralkyl or heterocyclic; R.sup.2 is lower alkyl, cycloalkyl or aralkyl, and X is O or NR.sup.5 wherein R.sup.5 is H or lower alkyl, and are HMG CoA reductase inhibitors and thus are useful as antihypercholesterolemic agents and in treating atherosclerosis.New intermediates for preparing the above seco-mevinic acid derivatives are also provided.

Abstract: A compound of the formula (I): ##STR1## wherein X is --CH.sub.2 -CH.sub.2 -- or --CH.dbd.CH--,Y is ##STR2## Z is an oxygen or sulfur atom, R.sup.1 and R.sup.2 are independently a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group and ring A is an optionally substituted 6-membered homocyclic ring,or its ester or salt which is useful as an inhibitory agent for the biosynthesis of the cholesterol.

Abstract: The invention concerns novel, pharmaceutically useful, benzheterocyclyl sulphones of the formula I: ##STR1## in which ring A may bear optional halogeno, (1-4C)alkyl or fluoro(1-4C)alkyl substituents; X is oxygen, or a group of the formula --S(O).sub.n -- or --NR.sup.1 -- in which n is zero, 1 or 2 and R.sup.1 is hydrogen, (1-4C)alkyl, (1-6C)alkanoyl, benzoyl or phenyl(1-4C)alkyl, the last two optionally substituted; Y is various linking groups defined hereinafter, such as ethylene or trimethylene; and in which the group --SO.sub.2 CH.sub.2 NO.sub.2 is located at position a, b or c in ring A; together with the non-toxic thereof. Other aspects of the invention include the production of the novel compounds by analogy processes and pharmaceutical compositions of the novel compounds for use in the treatment of diabetic complications.

Abstract: Compounds useful as antihypertensive agents, or antiviral agents against DNA containing viruses, such as herpes group viruses, are disclosed. The compounds are represented by Formula 1.0: ##STR1## and their pharmaceutically acceptable salts and solvates. Pharmaceutical compositions containing compounds represented by Formula 1.0 are disclosed. Also disclosed are methods of treating hypertension or a viral infection using compounds represented by Formulas 1.0.Also disclosed is a compound of Structure B ##STR2## useful as an intermediate in producing compounds of Formula 1.0. A process for preparing the compounds of Formula 1.0 is also disclosed. In the process a compound of Structure B ##STR3## is reacted with an alkoxide R.sub.1 O.sup.- M.sup.+ in a solvent comprising the corresponding alcohol R.sub.1 OH of the alkoxide. Optionally, an organic cosolvent may be used with the solvent.

Abstract: .alpha.-Homojirimycin and 6-dpi-homojirimycin are each synthesized from 2-azido-2-deoxy-3,4:6,7-di-O- isopropylidene-D-glydero-D-talo-heptono-1,5-lactone in which the side chain acetonide is hydrolyzed to give the corresponding diol which is then protected with a silyl protecting agent to form a silyl ether. The latter compound is used as a divergent intermediate in which the piperidine ring is formed by joining the nitrogen function at C-2 to C-6 (A) with inversion of configuration at C-6 to form 6-epi-homomannojirimycin or (B) with retention of configuration at C-6 to form .alpha.-homomannojirimycin.

Abstract: Isocoumarins with cationic substituents, their use in inhibiting serine proteases with trypsin-like, chymotrypsin-like and elastase-like specificity and their roles as anticoagulant agents, and anti-inflammatory agents.

Abstract: This invention relates to a process for preparing useful thromboxane A.sub.2 inhibiting (.+-.)7-[3.alpha.-[1-[[(phenylamino)thioxomethyl]hydrazono]ethyl]-1.alpha. ,4.alpha.-bicyclo[2.2.1]hept-2.beta.-yl]-heptenoic acids and useful derivatives thereof from (.+-.)octahydro-1.alpha.-methyl-3a.alpha.,7a.alpha.-4.alpha.,7.alpha.-meth ano-2H-inden-2-ones.

Abstract: Reactions of azide ion with 2-O-trifluoromethanesulphonates of both 3,4:6,7-di-O-isopropylidene-D-glycero-D-talo-heltono-1,5-lactone and of 3,4:6,7-di-O-isopropylidene-D-glycero-D-galactoheptono-1,5-lactone are disclosed to give predominantly 2-azido-2-deoxy-3,4:6,7-di-O-isopropylidene-D-glycero-D-galacto-heptono-1, 5-lactone initially which then isomerizes under moderate reaction conditions to 2-azido-2-deoxy-3,4:6,7-di-O-isopropylidene-D-glycero-D-talo-heptono-1, 5-lactone.

Abstract: A compound of the formula: ##STR1## wherein R is an unsubstituted benzyl group, a p-nitrobenzyl group, a benzyl group in which the phenyl group is substituted by one or two substituents selected from the group consisting of C.sub.1 -C.sub.4 alkyl groups and C.sub.1 -C.sub.4 alkoxy groups, a phenyl group which is substituted by a C.sub.1 -C.sub.4 alkylenedioxy group or by one or two substituents selected from the group consisting of C.sub.1 -C.sub.4 alkyl groups and C.sub.1 -C.sub.4 alkoxy groups, a C.sub.1 -C.sub.4 trialkylsilyl group, a mono-substituted C.sub.1 -C.sub.4 alkyldiarylsilyl group, a triarylmethyl group, a C.sub.1 -C.sub.4 acyl group, a substituted or unsubstituted benzoyl group, a C.sub.1 -C.sub.4 alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a tetrahydropyranyl group, a benzyloxymethyl group, or a methoxymethyl group.

Abstract: Chromogenic or fluorogenic silanes are formed in which a reactive organosilane is coupled to a chromogenic or fluorogenic nucleus of the coumarin class of compounds, by an ether, urethane or urea linkage. The preferred compounds have the general formula.X.sub.y R'.sub.z Si(CH.sub.2).sub.n L-Couwherein X is a displaceable or hydrolyzable group which allows the silanes to derivatize protic materials; R' is an aliphatic or aromatic hydrocarbon group; L is an ether (O), urethene (NCO) or urea (NCN) linkage; Cou is a coumarin derivative; n=1 to 8; y=1 to 3 and Z=0 to 2, such that y plus z equal 3. The ether linked silanes may be formed by hydrosilylation of an alkenyl ether of the coumarin compound, while the urethane or urea linked silanes may be formed by the direct reaction of a reactive silylisocyanate with a hydroxyl- or amine-substituted coumarin compound. The silanes are useful in derivatizing protic materials to provide the protic materials with chromogenic or fluorogenic properties.

Abstract: This invention relates to diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes wherein a substantial increase in opacification in the red and near infrared region of the visible spectrum and a substantial increase in opacification in the blue and green region is achieved by employing certain alkyl-substituted phenanthrol/carboxynaphthol phthaleins as the light-absorbing, pH-sensitive optical filter agent for the longer wavelength region of the visible spectrum.

Abstract: This invention relates to diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes wherein unexpectedly enhanced opacification in the red and near infrared region of the visible spectrum is achieved by employing phenanthrol/carboxynaphthol phthaleins as the light-absorbing, pH-sensitive optical filter agent for the longer wavelength region of the visible spectrum.

Abstract: Novel tricyclic compounds having a TXA.sub.2 -antagonizing activity represented by formula (I): ##STR1## which strongly antagonize an action of thromboxane A.sub.2 and are expected to have preventive and therapeutic effects on ischemica diseases, cerebro-vascular diseases, etc.

Abstract: Substituted isocoumarins, their preparation, their use in inhibiting serine proteases with trypsin-like, chymotrypsin-like and elastase-like specificity and their roles as anticoagulant agents, and anti-inflammatory agents.

Abstract: A compound of the formula ##STR1## in its d, l or dl form and mixtures thereof and their preparation and their use in the synthesis of pyrethrinoids.

Abstract: Optical indicator chalcogen (selenide or sulfide) compounds responsive to oxidants, e.g., hydrogen peroxide, and methods for preparing and using such indicators. Upon oxidation the resulting intermediate undergoes spontaneous elimination of the chalcogen residue to yield a signal compound which provides an optical signal such as fluorescence. Preferred fluorogenic indicator compounds are 3-chalcogen-3,4-dihydrocoumarin derivatives and 3-chalcogen-3,4-dihydro-2-quinolone derivatives. Such indicator compounds provide highly fluorescent products upon oxidation by hydrogen peroxide and are useful in analytical systems which generate hydrogen peroxide in response to the analyte under determination.

Abstract: A method for making a bicyclic lactone comprising heating under aqueous acidic conditions a beta, gamma unsaturated cyclic nitrile and an aldehyde, for a length of time sufficient to convert at least a portion of the reactants to a bicyclic lactone of the formula ##STR1## wherein R.sub.3 is --H; R.sub.4, R.sub.5, and R.sub.6 are independently selected from the group consisting of --H, --CH.sub.3 ; R.sub.2 is selected from the group consisting of --H, --CH.sub.3, and --CH.sub.3, and --C.sub.2 H.sub.5 ; R.sub.8 is --H or --CH.sub.3 ; m is an integer from 1 to 5; o is 0, 1, 2, or 3; and p is 0, 1, or 2; provided that the sum of m+o+p is an integer from 3 to 5; either R.sub.3 or R.sub.8 together with R.sub.7 represents a carbon-carbon bond. The method uses commercially available and relatively inexpensive raw materials as reactants.

Abstract: A compound of the formula ##STR1## wherein hydrogen, fluorine, chlorine or bromine; B is fluorine, or when A is fluorine B may be hydrogen;R is hydrogen, C.sub.1 -C.sub.8 branched or unbranched alkyl, CH.sub.2 BR, CH.sub.2 Cl or substituted or unsubstituted phenyl;X is hydrogen, chlorine or bromine;one of R.sub.1 and R.sub.2 is hydrogen and the other is hydroxy or C.sub.1 -C.sub.7 branched or unbranched alkoxy unsubstituted or substituted by a dialkyl amino group, or R.sub.1 and R.sub.2, taken together with the carbon atom to which they are linked, form the group ##STR2## with the proviso that, when R and X are both hydrogen, ##STR3## is a ##STR4## group, and B is fluorine and A is hydrogen is useful as antilimphoedema agent.

Abstract: New tetra-alkyl-2,2,5,5-cyclohexanone-4-ol-1-compounds and their sulphonyl derivatives with the general formula: ##STR1## in which: each of R and R', identical or different, represents an alkyl radical (1-5 carbons) and R" represents a hydrogen atom or a radical SO.sub.2 R"' in which R"' represents an alkyl radical (1-5 carbons) or an aryl radical (6-14 carbons), the process and the intermediates for their preparation, as well as their use in the synthesis of cyclopropane lactones of cis structure.

Abstract: Arenes, such as benzoic acid and substituted benzoic acids, are readily thallated by thallium(III) compounds such as the trifluoroacetate and subsequently reacted with palladium chloride and simple olefins, dienes, allylic halides, vinyl halides, vinyl esters, or unsaturated cyclopropanes or unsaturated cyclobutanes to give isocoumarins.

Abstract: Functionally substituted arenes selected from the group consisting of p-tolylacetic acid, N-methylbenzamide, benzamide and acetanilide which are thallated provide an organothallium salt which undergoes subsequent palladium promoted olefination to provide oxygen and/or nitrogen heterocycles such as ethers lactones, isoquinolones, indoles and isocarbostyrils.

Abstract: This invention relates to a novel N-acyl acidic amino acid diamide derivative represented by the general formula or a salt thereof: ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl or aralkyl group, or R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4, when taken together with the respective adjacent nitrogen atoms, form a substituted or unsubstituted heterocyclic group; R.sup.5 represents a substituted or unsubstituted cycloalkyl, acyl or heterocyclic group; A represents a bond or a substituted or unsubstituted alkylene, alkenylene or alkadienylene group; and n is 1, 2 or 3. Said compound has an anti-ulcer activity which is effective to human beings and animals. This disclosure relates to such a compound, to a process for the production thereof and to an anti-ulcer agent containing the same.

Abstract: There are described novel dyes of the formulae ##STR1## in which R.sub.1 and R.sub.2 independently of one another are each hydrogen, unsubstituted or substituted alkyl, cycloalkyl, aralkyl or aryl, and R.sub.1 and R.sub.2 together with the nitrogen atom, and optionally with the inclusion of further hetero atoms, can also form a 5- to 7-membered heterocycle, or one of the radicals R.sub.1 or R.sub.2 can be linked with the carbon atom, in the o-position with respect to the amino group, of the ring A to form a fused-on, saturated, unsubstituted or substituted 5- or 6-membered ring,X is .dbd.NR.sub.3, .dbd.NCOR.sub.4, ##STR2## .dbd.NH or .dbd.O, wherein R.sub.3 is alkyl or unsubstituted or substituted phenyl,R.sub.4 is unsubstituted or substituted alkyl, aralkyl, aryl, vinyl, alkoxy, phenoxy or amino, andR.sub.5 is cyano, carbalkoxy, or unsubstituted or substituted carbonamide, andR.sub.

Abstract: A compound of the formula: ##STR1## wherein u represents hydrogen, carboxamido, N-hydroxycarboxamido, carboxy, azido, an aryl, an acylamino, a protected carboxy or an N-alkoxycarboxamido, or, together with v, can represent --S-- or --CH.sub.2 S--; v represents hydrogen, halogen, cyano or an alkylthio, or, together with u, can represent --S-- or --CH.sub.2 S--, or, together with w, can represent --(CH.sub.2).sub.3 CO--; w represents hydrogen, carboamoyl, cyano, carboxy, an N-alkylcarbamoyl, an alkyl, an aryl, a protected carboxy or a heterocycle, or, together with v, can represents --(CH.sub.2).sub.

Abstract: There are described compounds of formula I, ##STR1## in which Ra, Rb, Rc, Rd, Re, Rf and Rg, which may be the same or different, each represent hydrogen, amino, hydroxy, alkoxy, alkenyloxy, halogen, acyl, alkenyl, alkyl, or alkoxy substituted by phenyl,Rh is hydrogen, alkyl or --COOH.X is a hydrocarbon chain containing from 2 to 10 carbon atoms and optionally substituted by a hydroxy group,A has no significance or represents Y, OY, or SY and Y represents a C 1 to 4 hydrocarbon chain which is optionally substituted by alkyl C 1 to 4,E and G, which may be the same or different, each represent --O--, --S-- or --CH.sub.2 --, provided that at least one of E and G is --O-- or --S--,L, together with the carbon atoms to which it is attached, forms a benzene, furan, thiophene, pyrrole, or pyran-2-one ring,and pharmaceutically acceptable derivatives thereof.

Abstract: A process for producing 3,3,7-trimethyl-2,9-dioxatricyclo[3.3.1.0.sup.4,7 ]nonane useful as an insect pheromone and having the formula, ##STR1## which comprises reducing 1,5,5-trimethyl-7-endo-tert-butyldimethylsilyloxy-4-oxabicyclo[4.2.0]octan -3-one with diisobutylaluminum hydride, and treating with an acid, after desilylation.

Abstract: Novel compounds of the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are H or alkyl and R is an optionally-substituted unsaturated, cycloalkyl, secondary-alkyl, aromatic or heterocyclic group, are useful as plant growth regulators and herbicides. Certain intermediates are also novel.

Abstract: There are described compounds of formula I, ##STR1## in which Ra, Rb, Rc, Rd, Re, Rf and Rg, which may be the same or different, each represent hydrogen, amino, hydroxy, alkoxy, alkenyloxy, halogen, acyl, alkenyl, alkyl, or alkoxy substituted by phenyl,Rh is hydrogen, alkyl or --COOH.X is a hydrocarbon chain containing from 2 to 10 carbon atoms and optionally substituted by a hydroxy group,A has no significance or represents Y, OY, or SY and Y represents a C 1 to 4 hydrocarbon chain which is optionally substituted by alkyl C 1 to 4,E and G, which may be the same or different, each represent --O--, --S-- or --CH.sub.2 --, provided that at least one of E and G is --O-- or --S--,L, together with the carbon atoms to which it is attached, forms a benzene, furan, thiophene, pyrrole, or pyran-2-one ring,and pharmaceutically acceptable derivatives thereof.

Abstract: Process for manufacturing chlorolactones by reacting, within an ahydrous organic solvent, a metal N-chlorosulfonamidate of the formula ##STR1## wherein R is a hydrogen or halogen atom or an alkyl radical, Ar is a mono- or polycyclic divalent aromatic radical and M is an alkali metal, with a substantially stoichiometrical proportion of an aliphatic or alicyclic carboxylic acid having at least one double bond separated from the COOH group by at least 2 carbon atoms, in the presence of a substantially stoichiometrical amount of a strong acid whose conjugate base is weakly nucleophilic.