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The tandem Michael-intramolecular Wittig reactions between cyclic phosphonium ylide and 8-phenylmenthyl cinnamate occurs with high diastereoselectivity and represents a novel stereoselective method for the preparation of multifunctionalized cycloheptane and acrylate derivatives.

The tandem Michael-intramolecular Wittig reactions of a five-membered cyclic phosphonium ylide with alpha,beta-unsaturated thioesters produced cycloheptene derivatives in 29-58% yield. The reaction proceeded through a rigid phosphabicyclic intermediate and supplied the cycloheptene derivatives with high stereoselectivity. On the other hand, although the reaction employing S-cyclohexyl cyclopentenethiocarboxylate as a substrate produced a 1:1 mixture of cis and tras adducts of the corresponding hydroazulene derivatives, the reaction of S-tert-butyl cyclopentenerthiocarboxylate afforded cis-adduct as a major product.

A study was conducted to characterize diastereoselective intramolecular Diels-Alder reactions of vinyl sulfones supporting dienes with a chiral building block at the allylic position. D-N-benzylphenylalanilol as utilized as a starting material for the intramolecular Diels-Alder reaction. Results indicated that the intramolecular Diels-Alder reactions of sulfonyl triene with an E-structure on the diene part supported a si-face selective exo-cycloaddition.

A novel method of synthesizing seven-membered cyclic enol ether derivatives was developed through the utilization of Michael-intramolecular Wittig reaction. The design featured the reaction of cyclic phosphonium with enoates and a rigid phosphabicyclic substrate as the starting material for generating enol ether derivatives with high stereoselectivity. The reaction mechanism indicated that trans enol ether derivatives were produced predominantly.

An ammonium salt of a diphenyl phosphine, on treatment with HCl and corresponding amines, gives cyclic amino phosphonium salts. The aza-Wittig reactions of these salts result in alkenylphosphine oxides, which can be further alkenated. These reactions find application in the syntheses of compounds like 1,4-diketones, hydroazulenes and cycloheptenyldiphenylophosphine oxide derivatives.

Focuses on the use of the L-amino acid as chiral building blocks to prepare the sulfonyl trienes which has a chiral center on the allyl carbon involving the diene moiety. Where the intramolecular diels-alder reaction of the sulfonyl trienes having E-geometry on the diene moiety proceeded on; Performance of the intramolecular diels-alder reaction in boiling benzene; Properties of these sulfonyl trienes.

States that the reaction of 1-cyclopentenyl ketones with 1,1-diphenylphospholanium ylide gave trans-hydroazulene derivatives with high diastereoselectivity via tandem Michael-intramolecular Wittig reactions. Method for the construction of trienes, unconjugated dienes and unconjugated enones.

Asymmetric monobenzoylation reactions of cyclic meso-1,3- and 1,4-diols were catalyzed by a phosphinite derivative of quinidine to afford the corresponding monobenzoylated diol with good yield and enantioselectivity. [reaction: see text]