Variation of the C1 component in the silicon-induced domino synthesis of cyclopentanes
摘要:
The reaction of mono- or bissilylated thioanisole derivatives 2b-e with 3,4-epoxybutyl tosylate (3) affords the cyclopentanols 6a-c. Migratory aptitudes of two different silyl groups in the Brook 1,4-rearrangement is examined starting from 2d, e giving the order SiMe2Ph > SiMe3 > SiMePh2. The relative configuration of the resulting 1,3-functionalized cyclopentanes is established by NOE experiments after derivatization of the alcohol to the corresponding pivalates 7a-c. (C) 1998 Elsevier Science Ltd. All rights reserved.
Variation of the C1 component in the silicon-induced domino synthesis of cyclopentanes
作者:Nico Bräuer、Tycho Michel、Ernst Schaumann
DOI:10.1016/s0040-4020(98)00697-8
日期:1998.9
The reaction of mono- or bissilylated thioanisole derivatives 2b-e with 3,4-epoxybutyl tosylate (3) affords the cyclopentanols 6a-c. Migratory aptitudes of two different silyl groups in the Brook 1,4-rearrangement is examined starting from 2d, e giving the order SiMe2Ph > SiMe3 > SiMePh2. The relative configuration of the resulting 1,3-functionalized cyclopentanes is established by NOE experiments after derivatization of the alcohol to the corresponding pivalates 7a-c. (C) 1998 Elsevier Science Ltd. All rights reserved.
ethylsilanes 12 by base-induced α-elimination. This is confirmed by [2+1] cycloadditions with alkenes to give the cyclopropanes 4a–d and 14. Product 4a is identical with the product obtained from carbanion 1c, phenyloxirane, and styrene, for which a carbene intermediate 5a had been invoked. On heating in the presence of copper triflate, cyclopropane 4a undergoes ringenlargement to the thiochroman