Transposition des bromo-2 benzopropionates d'ethyle, substitues en α par un groupe acetyl ou cyano, en acetyl-2 et cyano-2 benzopropionate d'ethyle。合成这些 d'oxo-3 cyclanecarboxylates d'alkyle a partir de β-cetoesters; 例如,l'iodomethyl-2 oxo-2 cyclopentanecarboxylate d'ethyle 导管 a l'oxo-3 cyclohexcarboxylate d'ethyle
A catalytic asymmetric intramolecular homologation of simple ketones with α‐diazoesters was firstly accomplished with a chiral N,N′‐dioxide–Sc(OTf)3 complex. This method provides an efficient access to chiral cyclic α‐aryl/alkyl β‐ketoesters containing an all‐carbon quaternary stereocenter. Under mild conditions, a variety of aryl‐ and alkyl‐substituted ketone groups reacted with α‐diazoester groups
Environmentally friendly TPDS-mediated free radical ring expansion of α-haloalkyl cyclic β-keto esters
作者:Masaaki Sugi、Hideo Togo
DOI:10.1016/s0040-4020(02)00241-7
日期:2002.4
Reactivities of tetraphenyldisilane (TPDS), tris(trimethylsilyl)silane, and tributyltin hydride in the radicalringexpansion of α-haloalkyl cyclic β-keto esters were examined. Among these reagents, TPDS was found most effective for the preparation of medium-sized cyclic compounds in terms of yields and ring-expansion/reduction selectivity.