A one-pot, lynchpin approach to 1,4-disubstituted E,E-butadienes via multiple cyanocuprate-mediated transmetalations
摘要:
Sequential transmetalation / Michael addition of E,E-1,4-bis-trimethylstannylbutadiene to enones using higher order cyanocuprates leads to products of double delivery in a 1-pot operation.
Triterpenoid total synthesis. Part 5. Synthetic disproof of the triterpene structure proposed for naurol A, a cytotoxic metabolite of a Pacific sponge
作者:Dai Nozawa、Hirosato Takikawa、Kenji Mori
DOI:10.1039/b002500n
日期:——
Naurol A is a cytotoxic metabolite isolated from a Pacific sponge, and 1 has been proposed as its structure. A mixture of (±)-1 and meso-1′ was synthesized from 4-tert-butyldimethylsilyloxy-3-methylcyclohex-2-en-1-one (6) employing the Stille coupling (10 + 11→1 + 1′) as the key step. Although the synthetic sample (1 + 1′) was a diastereomeric mixture at C-11, its spectral data (IR, UV, 1H and 13C