Acyclic stereocontrol via the claisen rearrangement: a formal synthesis of (+) tirandamycic acid
作者:Frederick E. Ziegler、Ronald T. Wester
DOI:10.1016/s0040-4039(00)99953-2
日期:1984.1
The optically active lactone 1a, prepared previously by the claisen rearrangement, serves as a starting material for the synthesis of (−) alcohol 7b which has been ultilized by Ireland in the synthesis of tirandamycic acid 8a.
Sparteine free Hoppe–Matteson–Aggarwal rearrangement was applied to various chiral acetonides. Utilizing different vinyl boronic esters a high level of substrate control was observed leading to excellent selectivities. These selectivities were attributed to stereoelectronic effects of the neighboring acetonide moiety. The obtained formal Felkin and anti-Felkin products feature up to four contiguous
The synthesis of the polypropionate chain of Streptovaricin U (1) is described utilizing a new approach for the stereoselective synthesis of the macrolide-type antibiotics via sulfur ylides.