stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. these phosphoranes undergo smooth intramolecular wittig reaction followedby an electrocyclic ring opening to produce dialkyl (e)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1h-imidazol-4-yl)fum...

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.

essential oils (eos) extracted from aerial parts of aster indamellus grierson, calamintha umbrosa benth. and erigeron annuus (l.) pres.were analyzed by gc, gc/ms. the major acetylenic constituent (cis-lachnophyllum ester) of e. annuus was isolated and characterized by 1h and 13c-nmr spectra. their toxicity and repellent effect against lipaphiserysimi was tested. oils of e. annuus and c. umbrosa...

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.

The copper-catalyzed conjugate addition-cycloacylation reaction of zinc homoenolatee with acetylenic esters or acetylenic amides is described. The zinc homoenolate is prepared from [ (ethoxycyclopropy1)oxyltrimethylsilane and zinc chloride in ether. Addition of an acetylenic amide or ester provides 2-carboxamidoor 2-carboalkoxy-3-alkylcyclopent-2-en-l-ones ingood to excellent yields. The reacti...

Acetylenic sulfones attached to solid supports by means of ester linkers were employed in a variety of cyclization and cycloaddition reactions, followed by cleavage of the products from the resin by ester hydrolysis or reductive desulfonylation.

the adducts produced in the reaction between trialkyl phosphites and acetylenic esters were trapped by hydantoins to produce highly functionalized dialkyl 2-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl) succinate in good yields.

A two-component condensation reaction between an electron-poor acetylenic ester and a phenol e ciently provides substituted aryl vinyl ethers in a one-pot reaction in the presence of dipotassium hydrogen phosphate in solvent-free conditions.

Multicomponent reactions involving azines (4-methylpyridine, isoquinoline and N-methyl imidazole) and acetylenic ester were undertaken in the presence of CH compound such as 2-furoyl trifluoroacetone(4,4,4-trifluoro-1-thiophen-2-yl-butan-1,3-dione) to generate enaminoesters as stable 1,4-diionic compounds in high yields.

Convenient and simple procedures for the synthesis of functionalized Quinoxaline derivatives were developed via one-pot four-component reaction of o-aminoanilin, acetylenic ester, and malonyl dichloride in the presence of K2 CO3 as effective base catalyst. These compounds widely are used in various industries like paint, pharmaceutical and medicine. Quinoxaline derivatives are also part of anti...