A convenient and diastereoselective route to homoallyl alcohols: Addition of (z)- or (e)-alkenyl-dimethoxyboranes to aldehydes
作者:Katsuramaru Fujitta、Manfred Schloser
DOI:10.1002/hlca.19820650415
日期:1982.6.16
(Z)-2-Butenyl-dimethoxyborane adds smoothly to propanal and benzaldehyde to afford the homoallyl alcohols (R*,R*)-1 and (R*,R*)-2, In contrast (E)-2-butenyl-dimethoxyborane leads to adducts having the (R*,S*)-configuration. Dimethoxy-(Z)-2-pentenylborane, dimethoxy-(Z)-(2-methyl-2-butenyl)borane and (2Z,4E)-or (2E,4Z)hexadienyl-dimethoxyborane, treated with propanal, give (R*,R*)-3, (R*,R*)-4, (E)
(Z)-2-丁烯基-二甲氧基硼烷平稳地添加到丙醛和苯甲醛中,得到均烯丙基醇(R *,R *)- 1和(R *,R *)- 2,相比之下(E)-2-丁烯基-二甲氧基硼烷生成具有(R *,S *)构型的加合物。二甲氧基-(Z)-2-戊烯基硼烷,二甲氧基-(Z)-(2-甲基-2-丁烯基)硼烷和(2 Z,4 E)-或(2 E,4 Z)己二烯基-二甲氧基硼烷,给出(R *,R*)- 3,(R *,R *)- 4,(E),(R *,S *)- 5和(Z),(R *,R *)- 5分别。暗示周环电子运动的过渡态模型与这些硼烷反应的区域和立体选择性结果完全吻合。