The spiroacetal [C(9)–C(20)] fragments of spirofungins A and B, antibiotics isolated from Streptomyces violaceusniger Tü 4113, were prepared from a known bromo alcohol derived from (S)-citronellal, using thermodynamically controlled iodolactonization and spiroacetalization as the key steps.
Synthesis of the spiroacetal parts of spirofungin A and B
作者:Yuko Shimizu、Hiromasa Kiyota、Takayuki Oritani
DOI:10.1016/s0040-4039(00)00371-3
日期:2000.4
The C9-C20 spiroacetal parts of spirofungin A and B, antifungal antibiotics from Strephomyces violaceusniger Tu 4113, were synthesized simultaneously from (S)-citronellyl bromide and (+/-)-epoxy alcohol via alkyne-lactone coupling reaction and diastereomeric separation. (C) 2000 Elsevier Science Ltd. All rights reserved.
Total Synthesis and Evaluation of Cytostatin, Its C10−C11 Diastereomers, and Additional Key Analogues: Impact on PP2A Inhibition
作者:Brian G. Lawhorn、Sobhana B. Boga、Scott E. Wolkenberg、David A. Colby、Carla-Maria Gauss、Mark R. Swingle、Lauren Amable、Richard E. Honkanen、Dale L. Boger
DOI:10.1021/ja066477d
日期:2006.12.1
The totalsynthesis of cytostatin, an antitumor agent belonging to the fostriecin family of natural products, is described in full detail. The convergent approach relied on a key epoxide-opening reaction to join the two stereotriad units and a single-step late-stage stereoselective installation of the sensitive (Z,Z,E)-triene through a beta-chelation-controlled nucleophilic addition. The synthetic