Methyl trans-12-octadecenoate-9,10-dz was obtained from methyl threo-12,13-dihydroxy-eis-9-octadecenoate by a sequence of reactions involving formation of an ethoxydioxolane, catalytic deuteration of the double bond, and conversion of the ethoxvdioxolane group to an ethylenic bond. Methyl cisand trans-12-oct;decenoate15,15,16,16-d. and methyl cisand trans-12-octadecenoate-9 ,10,15,15,16,16-d6 w...

A stereoselective synthesis of (6Z, 11Z)-octadecadienoic acid (1) and (6Z, 11Z)-eicosadienoic acid (2) from easily accessible pentane-1,5-diol (3) is described. Thus, compound 3 on pyranylation and oxidation gave the aldehyde 5 which was converted to the acid 7 by Wittig reaction with a suitable phosphorane. Its depyranylation and oxidation furnished the key aldehyde 9 which upon Wittig reactio...

the wittig reaction rate can be dramatically enhanced by irradiation of the reaction mixture containing an aldehyde or ketone; methoxymethyl(triphenyl)phosphonium chloride, potassium t-butoxide, and t buoh with a commercial microwave oven. carbonyl compound are converted to witting products within three min. in good yields.

an efficient three-component reaction of dialkyl acetylendicarboxylates and 2-pyrrolidin in the presence of triphenylphosphine produces dialkyl 2-(2-pyrrolidin-n-yl)-3-(triphenylphosphanylidene)succinate. these phosphoranes undergo mild intramolecular wittig reaction to produce dialkyl (e)-2-(4,5-dihydro-3h-pyrrol-2-yl)fumarate in excellent yields.

Practical stereoselective synthetic routes to the antihistaminic drug olopatadine and its E-isomer have been developed, the key steps being a trans stereoselective Wittig olefination using a nonstabilized phosphorus ylide and a stereoselective Heck cyclization. The stereoselectivity of the Wittig reaction depends on both the phosphonium salt anion and the cation present in the base used to gene...

Protonation of the reactive intermediates generated in the raction between dalkyl acetylenedicarboxylates and triphenylphosphine by isonitrosoacetophenone leads to vinyltriphenylphosphonium salts, which undergo intramolecular Wittig reaction to produce dalkyl 4-phenyl-N-hydroxypyrrole-2,3-dicarboxylates in moderate yields.

The Wittig reaction rate can be dramatically enhanced by irradiation of the reaction mixture containing an aldehyde or ketone; methoxymethyl(triphenyl)phosphonium chloride, potassium t-butoxide, and t BuOH with a commercial microwave oven. Carbonyl compound are converted to Witting products within three min. in good yields.

Trinuclear rare-earth-metal methylidene (CH2 2−) complexes are an emerging class of compounds that serve as methylidene transfer agents for methylenation of carbonyl compounds. Herein, the reaction of a trinuclear scandium methylidene complex with acetophenone was used as a model reaction of the multimetallic-cooperating methylidene transfer case, and its detailed mechanism has been investigate...

This communication reports the first use of the Wittig reaction to produce alkenylcarbaboranes.