.ALPHA.-Chlorinative homologation of .ALPHA.,.BETA.-unsaturated esters.
作者:EIICHI YOSHII、TORU KOIZUMI、TOSHIJI KAWAZOE
DOI:10.1248/cpb.24.1957
日期:——
Ketene triethylsilyl methyl acetals obtained by hydrosilation of α, β-unsaturated esters were reacted with phenyl (bromdichloromethyl) mercury to give homologated 2-chloroacrylates
The design of diastereoselective Mukaiyama-Michael reaction of ketene silyl acetal
作者:Junzo Otera、Yukihiro Fujita、Shunichi Fukuzumi
DOI:10.1016/0040-4020(96)00478-4
日期:1996.7
The highly diastereoselective Mukaiyama-Michaelreaction has been designed. Suppression of an electron-transfer process is crucial for this purpose and the following conditions should be satisfied. (1) TiCl4 is employed as a Lewisacid. (2) Ketenesilylacetals have bulky siloxy and/or alkoxy group(s). (3) α-Enones have a bulky acyl group. The excellent syn-selectivity up to a 99:1 ratio is attained