Asymmetric syntheses. Part VII. Asymmetric reduction of ketones and alk-2-en-4-yn-1-ols with a lithium bismenthyloxyaluminium hydride complex; determination of the absolute configurations of allenic alcohols
作者:R. James D. Evans、Stephen R. Landor、John P. Regan
DOI:10.1039/p19740000552
日期:——
the former from (–)-(S)-α-chloroethyl 1-methylprop-2-ynyl ether involving elimination of hydrogen chloride followed by a Claisen sigmatropic rearrangement, and reduction of the resulting aldehyde. Asymmetric reduction of 4-methyl- and 4,4-dimethyl-pentan-2-ones with lithium bismenthyloxyaluminium hydride gave partially resolved (+)-4-methyl- and 4,4-dimethyl-pentan-2-ols.
(+)-己-和(+)-庚-3,4-二烯醇可通过用二薄荷基氧基铝氢化锂还原六-和庚-2-en-4-yn-1-醇而容易地获得。已显示两个二烯酚均具有(+)- S-构型;前者由(–)-(S)-α-氯乙基1-甲基丙-2-炔基醚合成,其中涉及消除氯化氢,然后进行克莱森(Claisen)σ重排,并还原生成的醛,从而证实了这一点。用二薄荷基氧基铝氢化锂不对称还原4-甲基-和4,4-二甲基-戊烷-2-酮,得到部分拆分的(+)-4-甲基-和4,4-二甲基-戊烷-2-醇。