我们报告了 (+)-1-de乙酰caesalmin C、(+)-δ-caesalpin、(+)-norcaesalpinin MC 和 (+)-norcaesalpinin P 的首次对映选择性全合成。合成策略的显着特征是外切-呋喃醌单缩酮的选择性分子内狄尔斯-阿尔德反应,随后对所得五环糠基缩酮进行化学选择性还原,提供关键中间体。后者可以通过实施立体选择性氧化来收集天然产物。在获得了卡桑呋喃二萜类化合物后,我们揭示了以前未知的生物活性:(+)-1-脱乙酰凯撒明 C 刺激棕色脂肪细胞的呼吸,这被认为在肥胖治疗中发挥着核心作用。
of a 4-hydroxy-2-pyrone derivative as a key reaction; and (iii) stereoselective dihydroxylation to give the diol derivative, followed by deoxygenation. Accordingly, we defined the absolute structures of arisugacins A and B as 4a-(R),6a-(R),12a-(R), and 12b-(S). Finally, we characterized the bioactivities of the synthetic intermediates to understand the structure–activity relationships of the arisugacins
Enantioselective route to a key intermediate in the total synthesis of forskolin
作者:E.J. Corey、Paul Da Silva Jardine、Tetsuya Mohri
DOI:10.1016/s0040-4039(00)82359-x
日期:1988.1
An enantioselective route for the totalsynthesis of forskolin, a potent activator of adenylate cyclase, has been developed which is based on reduction of dienone 3 to the (S)-alcohol 4 and conversion in two steps to tricyclic lactone 9, obtained in optically pure form simply by recrystallization.
Treatment of the enynols (1), (2), (3), and (5) with 35% perchloric acid in tetrahydrofuran produces, through a series of protoropic shifts, the corresponding dienones (4) and (11).