[2,3]-Thia-Wittig rearrangements with A marked starting material dependence of stereoselectivity
作者:Holger von der Emde、Reinhard Brückner
DOI:10.1016/s0040-4039(00)60177-6
日期:1992.11
[2,3]-Thia-Wittig rearrangements were initiated (a) by Sn,Li exchange of stannyl sulfides type 5 (X = S) and (b) by reductive lithiation of S,S-acetals type 6 (X = S). Homoallyl thiols were obtained in yields between 49 and 96%. E:Z selectivities of these rearrangements were low while syn:anti selectivities could be high. Extent and sense of both kinds of stereocontrol depended on whether procedure
[2,3] -Thia-Wittig重排是由(a)通过5型苯乙烯锡硫化物的Sn,Li交换(X = S)和(b)通过S,S-乙缩醛类型6(X = S)的还原锂化引发的。。得到的均烯丙基硫醇的产率在49%至96%之间。这些重排的E:Z选择性低,而Syn:反选择性可能高。两种立体声控制的程度和意义取决于是否采用了程序(a)或(b)。