Preparation of functionalized zinc borates and their coupling reaction with allylic acetates
作者:Yuichi Kobayashi、Yuko Tokoro、Kengo Watatani
DOI:10.1016/s0040-4039(98)01639-6
日期:1998.10
Several methods were examined to prepare functionalized boronate esters 4a-g. Thus, reaction of the lithium anions with B(O-i-Pr)(3) followed by esterification with 2,3-butanediol afforded 4a,b,d,e. The Masamune-Wittig reaction was applied to the boronate ester 4a to expand the carbon chain giving 4c and 4f The alkenyl boronate ester 4g was prepared from acetylene 10 by hydroboration using (Ipc)(2)BH followed by the ligand exchange reaction. (C) 1998 Elsevier Science Ltd. Ali rights reserved.