A method for the bromination of α‐diazo phenylacetate derivatives using cobalt(II) bromide is described. This bromination reaction features a short reaction time, broad substrate scope, operational simplicity, acid‐free conditions, and gram‐scalability.
A visible-light-induced bromination of α-diazo compounds by using bromoform as bromine source was developed, providing a green synthetic route to α-bromoesters. This protocol features no use of a photocatalyst or an additive, and a broad substrate scope. Its practicality was demonstrated by the gram-scale reaction and several valuable follow-up transformations.
A convenient entry into the rhoeadan skeleton. Total synthesis of (±) <i>cis</i>-alpinigenine
作者:Ijaz Ahmad、Victor Snieckus
DOI:10.1139/v82-385
日期:1982.11.1
provides the aminolactone 9a which by diisobutylaluminumhydride reduction followed by polyphosphoric acid mediated cyclization gives the tetracyclic product 10a, thus constituting a convergent, short entry into the rhoeadan alkaloid skeleton. Chromium trioxide oxidation of 10a affords a low yield of the corresponding lactone 11a. A parallel series of reactions starting from 7,8-dimethoxy-4-bromoisochroman-3-one