group was reacted with a phenolate ion, an optically active (R)-s-butyl phenyl ether was obtained with an inversion of the configuration at the chiral carbon atom. A reaction mechanism via a sulfurane intermediate is proposed for the alkylation of the phenolate ion with alkylsulfonium salts. The relative reactivities for the alkylation of several nucleophiles with dialkylphenylselenonium salts (12) were
A new asymmetric alkylation of cyclic β-keto esters with optically active sulfonium salts, which are easily prepared by optical resolution methods, has been investigated. Relative reactivities for alkyl substituents are found to be quite different from those for SN2 alkylation. Stereochemical reaction course via S–O sulfurane intermediate for this new reaction is proposed.
Alkylation of the enolateanion of 2-methoxycarbonyl-1-indanone with optically active dialkylphenyl selenonium salt resulted in the formation of optically active C-alkylated products. Absolute configuration of the optically active selnonium ion was estimated on the basis of the asymmetric alkylation and CD spectra.
2-甲氧基羰基-1-茚满酮的烯醇阴离子与旋光二烷基苯基硒盐的烷基化导致形成旋光C-烷基化产物。基于不对称烷基化和 CD 光谱估计光学活性硒离子的绝对构型。
Asymmetric alkylation of .beta.-keto esters with optically active sulfonium salts