Asymmetric Induction via an Intramolecular Haloetherification Reaction of Chiral Ene Acetals: A Novel Approach to Optically Active 1,4- and 1,5-Diols
作者:Hiromichi Fujioka、Hidetoshi Kitagawa、Yasushi Nagatomi、Yasuyuki Kita
DOI:10.1021/jo960714l
日期:1996.1.1
An asymmetric synthesis of chiral 1,4- and 1,5-diols has been developed from the ene acetals 1a and 1c, prepared from the corresponding aldehydes and chiral C(2)-symmetric diols, involving remote asymmetric induction as a key step. In the first step, treatment of 1 with I(coll)(2)ClO(4) in the presence of an alcohol afforded the macrocyclic acetals (3-5 and 7) in a highly stereoselective manner. Subsequent
已从烯缩醛1a和1c(由相应的醛和手性C(2)对称二醇制备)开发了手性1,4-和1,5-二醇的不对称合成,其中关键步骤涉及远程不对称诱导。第一步,在醇存在下用I(coll)(2)ClO(4)处理1,以高度立体选择性的方式得到大环缩醛(3-5和7)。随后碘化物的亲核取代,然后进行格里雅德反应,并完全保留了立体化学,并最终使二苯乙烯或二苯丙烯单元脱保护,从而以良好的收率成功制得了具有光学活性的1,4-和1,5-二醇。