Abstract: The present invention relates to an improved process for the in situ preparation of diisopinocampheylchloroborane which comprises reacting sodium borohydride and boron trichloride with .alpha.-pinene. The diisopinocampheylchloroborane thus obtained may be used, without isolation, to reduce prochiral ketones to their corresponding alcohols in high optical purity.

Abstract: A new process is described for the synthesis of the triazolyl tryptamine: ##STR1## and related compounds. The process involves a palladium-catalyzed ring closure between a substituted ortho-iodoaniline and a protected 1-alkynol. The process is carded out at high temperature, e.g. 100.degree. C., in a dry inert solvent, e.g., DMF and in the presence of a proton acceptor, e.g., Na.sub.2 CO.sub.3 or a trialkylamine. The triazolyl tryptamine, as well as acid addition salts thereof, is a 5 HT.sub.1 D receptor agonist having anti-migraine properties.

Abstract: The present invention relates to an improved process for the in situ preparation of diisopinocampheylchloroborane which comprises reacting sodium borohydride and boron trichloride with .alpha.-pinene. The diisopinocampheylchloroborane thus obtained may be used, without isolation, to reduce prochiral ketones to their corresponding alcohols in high optical purity.

Abstract: This invention relates to a method for the preparation of a compound of formula I: ##STR1## a key intermediate in the synthesis of a series of Angiotensin II receptor antagonists. The invention also relates to a selective reagent for conducting the Hofmann rearrangement, particularly in the formation of a pyridinoimidazolone, which is a percursor to the formation of an imidazopyfidine of formula I. This invention also relates to a method for the preparation of imidazolutidine, a key intermediate in the synthesis of 3-(2'-(N-benzoyl)sulfonamidobiphen-4-yl)-methyl-5,7 -dimethyl-2-ethyl-3H-imidazo[4,5-b]pyridine, using pyridinoimidazolone, an unreactive urea.

Abstract: Method for the preparing biphenyltetrazole compounds which are angiotensin II receptor antagonists or which are useful intermediates to prepare angiotensin II receptor antagonists. An illustrative biphenyl tetrazole compound is 2-n-butyl-4-chloro-1-[(2'-(tetrazol-5-yl)-1,1'-biphenyl-4-yl)methyl]-1H-im idazole-5-methanol, potassium salt.

Abstract: The natural stereochemistry at the 13-position of avermectin aglycones, normally .alpha.-oriented or below the plane of the molecule, is inverted or epimerized into the .beta.-position. The procedure starts with the avermectin aglycone compounds where the 13.alpha.-hydroxy group is activated to a mesylate leaving group. The resultant 13-.alpha.-mesylate is then displaced with a cesium carboxylate and one equivalent of the respective carboxylic acid, ending with the ester group being converted to the 13-.beta.-hydroxy configuration by transesterification in high yield.

Abstract: A process is described for the racemization of an optically active carboxylic acid of structure (I): ##STR1## which comprises the treatment of (I) with an acid anhydride and its conjugate base.

Abstract: A process is described for the preparation of an optically active carboxylic acid or ester derivative thereof from a ketene and an optically active .alpha.-hydroxyester or an .alpha.-hydroxy amide.

Abstract: (+)-trans-1a,2,3,4a,5,6-Hexahydro-9-hydroxy-4-propyl-4H-naphth[1,2-b]-1,4-o xazine is elaborated by a series of process steps that retain the enantiomeric purity of the starting material, D-aspartic acid. The product is a direct acting dopaminergic agent, useful in the treatment of Parkinson's disease.

Abstract: An apparatus for delimbing felled trees is described, wherein the trees are pulled individually or, in some cases, in bundles through the delimber. The delimber is provided with a base; a lower impact shear blade which is a notched steel plate supported upon the base, the notch bounding the under half circumference of a tree in the delimber; upper impact shear blades which are a pair of arcuate arms pivoted on the base, designed and arranged such that a tree resting in the notched plate is bound substantially about its upper half circumference by the arcuate arms pivoted into contact with the tree; and an activating plate, pivoted upon the base, interconnected with the arcuate arms such that the weight and force of a tree pulled through the delimber in contact with the notched plate, acts upon the activating plate causing it to pivot thereby pulling the arms into contact with the tree.