New methods for reductive free-radical cyclizations of α-bromoacetals to 2-alkoxytetrahydrofurans with activated chromium(II)-acetate
作者:Claus Hackmann、Hans J. Schäfer
DOI:10.1016/s0040-4020(01)81285-0
日期:1993.5
free-radical cyclization of α-bromoacetals 4 to 2-alkoxytetrahydrofurans 5 in 54–93% yield induced by activated chromium(II)-acetate. Four new methods have been developed in order to activate the transition metal. Two of them require only catalytic amounts of chromium(II)-acetate, because it can be regenerated in situ chemically or electrochemically. The diastereoselectivity of the cyclization depends on
Sonochemical Acceleration of Conversion of 2-Alkoxytetrahydrofurans to γ-Butyrolactones Synthesis of (±)-Quercus Lactone-A
作者:A. Srikrishna、S. Nagaraju、G. V.R. Sharma
DOI:10.1080/00397919208021096
日期:1992.4
Effect of sonochemical irradiation on the conversion of 2-alkoxytetrahydrofurans to γ-butyro-1actores by Jones reagent, and its extension to the highly stereoselective synthesis of quercus lactone a, is reported.
报道了声化学辐照对琼斯试剂将 2-烷氧基四氢呋喃转化为 γ-丁酰-1actores 的影响,并将其扩展到栎属内酯 a 的高立体选择性合成中。