Synthetic Studies on Biscembranoids. Asymmetric Total Synthesis of the 14-Membered Diene Unit of Methyl Sarcophytoate
作者:Minoru Yasuda、Mitsuaki Ide、Yuka Matsumoto、Masaya Nakata
DOI:10.1246/bcsj.71.1417
日期:1998.6
6-octadienal (7), which was also prepared from geraniol, gave a 1 : 1 separable mixture of the adducts (17 and 18). Reduction of the carbonyl group in 17 and 18, followed by regioselective oxidation of the allylic hydroxy group, afforded α,β-unsaturated ketone, (2E,6E,10R,11R,12S)-1-(2,2-dimethylpropanoyloxy)-10-hydroxy-11,12-(isopropylidenedioxy)-3,7,11,15-tetramethyl-2,6,14-hexadecatrien-8-one (5)
14 元二烯单元 (1S,2S,4E,6E,10S,11Z,14R)-10,14-epoxy-4-isopropenyl-1,7,11-trimethyl-4,6 的不对称全合成, 11-cyclotetradecatriene-1,2-diol (3), 肌醇酸甲酯 (1) 已经实现。甲基酮,(3S,4S)-3,4-(isopropylidenedioxy)-3,7-dimethyl-6-octen-2-one (6),是通过 Sharpless 不对称环氧化和区域选择性环氧化物开环反应从香叶醇对映选择性制备的. 6 的烯醇锂与醛之间的羟醛偶联,(2E,6E)-2,6-二甲基-8-(2,2-二甲基丙酰氧基)-2,6-辛二烯醛 (7),也由香叶醇制备,得到加合物(17和18)的1:1可分离混合物。还原 17 和 18 中的羰基,然后对烯丙基羟基进行区域选择性氧化,得到 α,β-不饱和酮,(2E