Abstract: In one aspect, compounds of Formulae (I) and (II), or pharmaceutically acceptable salts thereof, are featured; Formula (I), Formula (II) or a pharmaceutically acceptable salt thereof, wherein the variables shown in Formulae (I) and (II) can be as defined anywhere herein.

Abstract: A process for preparing trioxane by converting methanol to formaldehyde by dehydrogenation at a temperature of 300 to 1000° C., in the presence of a catalyst, wherein the catalyst is generated physically separately from the reactor and at a temperature above the dehydrogenation temperature, and trimerizing the formaldehyde prepared in this way to give trioxane. Also described is a process for preparing polyoxymethylene and polyoxymethylene copolymers from the formaldehyde.

Abstract: The invention relates to a process for preparing 2,7-dimethyl-2,4,6-octatrienal monoacetals of the general formula I which comprises a) condensing an ester phosphonium salt of the general formula II or an ester phosphonate of the general formula III with an aldehyde of the formula IV in a Wittig or Wittig-Horner reaction to give an acetal ester of the general formula V b) reducing the ester of the formula V to give an acetal alcohol of the general formula VI and c) oxidizing the alcohol to 2,7-dimethyl-2,4,6-octatrienal monoacetals of the general formula I, where the substituents have the meaning defined in the description.

Abstract: An unsaturated fatty acid precursor of a natural 1,3-diol derivative, which precursor is the same as that which is naturally present in a cider apple, is enzymatically converted to the natural 1,3-diol derivative.

Abstract: A process for preparing acetals of the formula I where a) the Rs are, independently of one another, a C1-C20-alkyl or C3-C20-alkenyl radical, or b) the two R radicals together form the members of an unsubstituted or C1-C10-alkyl-substituted 5- to 7-membered cyclic acetal, by reacting 3-methyl-2-butenal in the presence of sulfamic acid, of a N-(C1-C8-alkyl)sulfamic acid or of a N,N-di(C1-C8-alkyl)sulfamic acid as catalyst with: an alcohol of the formula R—OH (IIa), or an orthoester of the formula HC—(OR)3 (III) or a mixture of an alcohol of the formula (IIa) and an orthoester of the formula (III), or an alcohol of the formula HO—(CH2)m—OH (IIb), where m is a number from 2 to 4, and (CH2)m group in the alcohol IIb may be substituted by a C1-C10-alkyl group.

Abstract: The present invention relates to a method for preparing optically active 5-methtyl-2-(1-methtyl-butyl)-5-propyl-1,3-dioxan, wherein said method comprises the following steps: converting lactic acid methylic ester into the corresponding N,N-disubstituted amid (aminolysis with piperidine and/or pyrrolidine); protecting its free OH function by a reaction with ethylvinylether in the presence of p-pyridiniumtosylate as a catalyst; submitting the N-pentamethylen- or N-tetramethylenlactamide thus obtained to a Grignard reaction in a conventional way so as to produce the corresponding &agr;, &bgr;-unsaturated ketone; further separating in a conventional way (e.g. agitation with acetic acid) the protection group introduced during the second step; acetalating in a conventional way the ketone function (e.g.

Abstract: A method for preparing 1,3-dioxane compounds of the formula (I): ##STR1## wherein R.sup.1 and R.sup.2, independently of one another, represent hydrogen or a hydrocarbon radical; and X.sup.1 and X.sup.2, independently of one another, represent an electronegative groups, which method entails reacting a bis(hydroxymethyl) compound of the formula (II): ##STR2## in which X.sup.1 and X.sup.2 each, independently of one another, are as defined above, with an orthocarboxylic acid ester of the formula R.sup.4 --C(OR.sup.5).sub.3 (III), in which R.sup.4 represents hydrogen or a hydrocarbon radical and R.sup.5 represents a hydrocarbon radical, and with an aldehyde or ketone of the formula R.sup.1 --CO--R.sup.2 (IV), in which R and R each, independently of one another, are as defined above.

Abstract: Cyclohexenone oxime ethers ##STR1## where R.sup.1 is alkyl;A is substituted or unsubstituted alkylene or alkenylene, where methylene is replaced by an oxygen atom, a sulfur atom, a sulfoxyl group, a sulfonyl group or --NR.sup.a --,Z is phenyl or a 5- or 6-membered heteroaromatic structure;X is substituted or unsubstituted amino, nitro, cyano, halogen, alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -haloalkyl, C.sub.1 -C.sub.4 -haloalkoxy, carboxyl, C.sub.1 -C.sub.4 -alkoxycarbonyl, substituted or unsubstituted benzyloxycarbony or phenyl;n is 0 to 3, or 1 to 5 where X is halogen;R.sup.

Abstract: An improved process for the preparation of cyclic ketene acetals such as 2-methylene-1,3-dioxepane is provided. This process entails reacting at an elevated temperature a halogenated cyclic ketene acetal such as 2-chloromethyl-1,3-dioxepane with a hydroxide compound such as potassium hydroxide in a non-reactive alcohol such as 2-butanol.

Abstract: Compounds of the formula ##STR1## wherein R.sup.1 is hydrogen or straight-chain alkyl; R.sup.2 is --CN, --R, --COR, --COOR or when R.sup.2 is positioned on an aromatic ring R.sup.2 also can be --OR, --OOCR or --F; R is alkyl; A is a group with 1 to 4 six-membered rings, these rings being linked directly with one another and with ring B in each case via a single covalent bond or being linked at one or two positions also via --COO--, --OOC-- or --CH.sub.2 CH.sub.

Abstract: The invention relates to nematic liquid crystals, especially for electro-optical components for the modulation of transmitted or reflected light, as well as for the display of numbers, symbols and images, exhibiting favorable physical characteristics, as well as to a method for the production of the new substances.It has been found that new liquid crystal 2-substituted-1,3-dioxane-5-carboxylic acid esters of the general formula ##STR1## are suited for use in electro-optical components for the modulation of the light, as well as for the display of numbers, symbols and images, and can be used alone, in mixtures with each other and/or in mixtures with additional liquid crystal or non-liquid crystal substances.