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.
DOWD, PAUL;CHOI, SOO-CHANG, TETRAHEDRON, 45,(1989) N, C. 77-90
作者:DOWD, PAUL、CHOI, SOO-CHANG
DOI:——
日期:——
α-VINYLATION OF TERTIARY ACTIVE HYDROGEN COMPOUNDS
作者:Richard A. Bunce、Scott E. Burns
DOI:10.1080/00304949909355677
日期:1999.2
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.