Studies in macrolide synthesis: A stereocontrolled synthesis of a (9S)-macrolide intermediate for oleandomycin using chiral boron reagents.
摘要:
The (9S)-macrolide 1 (P = TBS) was prepared in 14 steps (5% yield) with 63% overall ds starting from the ethyl ketone (S)-2. The C1-C7 and C8-C13 segments, 3 and 4, were obtained via boron enolate aldol reactions mediated by (+)- and (-)-(Ipc)2BOTf, respectively.
Total Synthesis of the Polyene-Polyol Macrolide RK-397, Featuring Cross-Couplings of Alkynylepoxide Modules
作者:Svetlana A. Burova、Frank E. McDonald
DOI:10.1021/ja039618+
日期:2004.3.3
from alkyne-epoxide couplings are converted into 1,3-diols by a sequence of hydroxyl-directed hydrosilylation, C-Si bond oxidation, and stereoselective ketone reduction with induction from the beta-hydroxyl group. The highly convergent nature of our synthetic pathway and the flexibility of the modular synthesis strategy for virtually any stereoisomer can provide access to other members of the polyene-polyol
A stereocontrolled total synthesis of the orthinine decarboxylase inhibitors saliniketals A and B is described. Key features of the 17-step route include the use of two boron aldol/reduction sequences to control six of the nine stereocenters, an intramolecular Wacker-type cyclization to install the bicyclic acetal core, and a late-stage Stille coupling to append the requisite (2 Z,4 E)-dienamide.