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 novelfreeradical initiated ring expansion of haloalkyl β-keto esters is described. Following alkylation of the β-keto ester with the appropriate dihalide, the resulting halide is treated at reflux with tri-n-butyltin hydride. Rearrangement to the homologated γ-keto ester occurs smoothly. An oxy radical intermediate is proposed for the reaction.
Free radical ring expansion by three and four carbons
作者:Paul Dowd、Soo Chang Choi
DOI:10.1021/ja00255a071
日期:1987.10
Nouvelle methode d'agrandissement de cycles de β-ceto esters a 5, 6, 7 carbones par une reaction radicalaire regioselective pour acceder a des cycles a 8, 9, 10, 11 atomes de carbone
Nouvelle methode d'agrandissement de Cycles de β-cetoesters a 5, 6, 7 carbones par une 反应激进分子区域选择性倾倒剂 a des Cycles a 8, 9, 10, 11 atomes de carbone
Reduction of 2-Alkyl-2-carbomethoxy-cyclopentanone Derivatives with Sodium Borohydride. II. The Elucidation of the Diastereoselective Control<sup>a</sup>
作者:Lis H. P. Teixeira、Eliezer J. Barreiro、Carlos A. M. Fraga
DOI:10.1080/00397919708004185
日期:1997.9
Abstract The synthesis and reduction of four new 2-substituted β-keto-ester derivatives (6–9), employing inexpensive sodium borohydride, were achieved to evaluate the diastereoselectivity of the reduction process of 2-allyl-2-carbomethoxy cyclopentanone derivative (1a) in the same conditions. These results indicating that the diastereoselective control in this process depend on blockage of the re-face