Lipids were extracted from excised uropygial glands of domestic chickens and the wax diesters were isolated by preparative thin-layer chromatography (TLC). The diesters were hydrolyzed and the liberated diols were resolved by boric acid TLC into two fractions. These were investigated by proton magnetic resonance at 360 MHz of the free diols and of their acetonide derivatives. The results showed...

[reaction: see text] The beneficial influence of cis-isopropylidene acetal tether control groups, to facilitate the asymmetric synthesis of substituted decalins by intramolecular Diels-Alder reactions, is described. Compared to trans-acetonides, these cases proceed under milder conditions to afford the cis-fused adducts from an endo transition state. An unusual acetonitrile solvent effect exert...

Natural monoglycerides of cinnamic, ferulic and p-coumaric acids were synthesized in good to high overall yields from isopropylidene glycerol via the Mitsunobu reaction and further deprotection of the corresponding acetonides with Amberlyst 15. The method avoids the need of protection of the phenolic hydroxyls. During the Mitsunobu esterifications a strong influence of the acid strength on the ...

[reaction: see text] A new method to facilitate the separation of diastereomeric syn- and anti-1,3-diols is described. The method relies on the different hydrolysis rates of the corresponding diastereomeric acetonides. Treatment of a dichloromethane solution of syn- and anti-1,3-diol-acetonide with a catalytic amount of diluted aqueous hydrochloric acid leads to the selective cleavage of the an...

tert-Butyl thymidylate 3 was prepared from thymidine 1 in six steps and 67% overall yield. When the lithium trianion of 3 (prepared by treatment of 3 with excess LDA and then excess tert-butyllithum) is reacted with electrophiles, trapping occurs stereoselectively from either the alpha- or beta-face depending on the electrophile (Scheme 1). Deuterioacetic acid in deuteriomethanol affords mainly...

A new synthesis of a-hydroxycarboxylates and 2-hydroxybenzoates based on the reaction of acetonides of a-hydroxycarboxylic acids and 2-hydroxybenzoic acid with sodium alkoxides in the corresponding alcohols as solvent is described. In general, decreasing the steric hindrance of the reactants and increasing the boiling points of alcohols increased the yiel...

a new synthesis of a-hydroxycarboxylates and 2-hydroxybenzoates based on the reaction of acetonides of a-hydroxycarboxylic acids and 2-hydroxybenzoic acid with sodium alkoxides in the corresponding alcohols as solvent is described. in general, decreasing the steric hindrance of the reactants and increasing the boiling points of alcohols increased the yields and decreased the required time for t...