Cochleamycin A (1) was synthesized in 2.4% overall yield via a 23-step linear sequence starting from 3-butene-1-ol. Key features of the synthesis include the synthesis of (2)-1,3-diene 21 via a Stille coupling of 4 and 5 and a transannular Diels-Alder reaction of macrocycle 26 to provide the complete carbon skeleton of 1.
Catalytic enantioselective allylboration of propargylic aldehydes
作者:Urmibhusan Bhakta、Erin Sullivan、Dennis G. Hall
DOI:10.1016/j.tet.2013.11.095
日期:2014.1
Homoallylic propargylicalcohols are important building blocks in natural product synthesis. This moiety can be transformed into various other structures by performing other known transformations, which can in turn lead to the synthesis of biologically useful compounds. Herein, a methodology based on Lewisacid assisted Brønstedacid catalysed allylboration of propargylic aldehydes is described. A
ENHANCEMENT OF ERYTHRO-SELECTIVITY IN THE [2,3]-WITTIG REARRANGEMENT OF CROTYL PROPARGYL ETHER SYSTEM AND ITS USE IN THE STEREOCONTROLLED FORMAL SYNTHESIS OF (±)-OUDEMANSIN
作者:Koichi Mikami、Ken-ichi Azuma、Takeshi Nakai
DOI:10.1246/cl.1983.1379
日期:1983.9.5
The [2,3]-Wittig variant of (Z)-crotyl ether involving trimethylsilylethynyl (or 1-propynyl) group as the key substituent on the carbanion terminus exhibits an exceptionally high level of erythro-selection, and its synthetic potential is illustrated in the formal synthesis of antibiotic (±)-oudemansin.