[1,2]-Wittig Rearrangement of Acetals III [1]. New 1,2-Alkoxyalcohols, 1,2-Alkoxyaminesand 1,2-Dialkoxy Compounds as Chiral Ligands for Organomagnesium and Organolithium Compounds and forLithium Aluminum Hydride
作者:Peter Gärtner、Martin Letschnig、Max Knollmüller
DOI:10.1007/s007060070064
日期:2000.8.22
2-alkoxyoctahydro-7,8,8-trimethyl-4,7-methanobenzofurans via a [1,2]- Witting rearrangement and subsequent substitution were synthesized and tested as additives for the enantioselective addition of butyllithium and butylmagnesium chloride to benzaldehyde and for the reduction of acetophenone with lithium aluminum hydride. The selectivity of the reactions was determined by GC of the obtained 1-phenyl-1-pentanol
八O-取代1,2-二醇和一个O,N-取代的1,2-氨基醇由2- alkoxyoctahydro-7,8,8三甲基-4,7- methanobenzofurans衍生 经由 一个[1,2] - 维悌希 重排合成了随后的取代基并进行了取代,并测试了将丁基锂和丁基氯化镁对映选择性地加到苯甲醛中以及用氢化铝锂还原苯乙酮的添加剂。反应的选择性通过在手性相上获得的1-苯基-1-戊醇和1-苯基乙醇的GC确定。选择性方面的最佳结果(52% ee 和94% ee 通过向有机金属试剂中加入取代的1,2-氨基醇形成1-苯基-1-戊醇,以及使用α-烷氧基 醇(62%ee )还原苯乙酮,可实现上述目的 。