Chiral Decalins: Preparation from Oleanolic Acid and Application in the Synthesis of (−)-9-<i>epi</i>-Ambrox
作者:Hai-Jun Yang、Bo-Gang Li、Xiao-Hua Cai、Hua-Yi Qi、Ying-Gang Luo、Guo-Lin Zhang
DOI:10.1021/np060159a
日期:2006.11.1
(4) and its C-3 hydroxyl derivative 5 from oleanolic acid (3beta-hydroxyolean-12-en-28-oic acid, 1). Three key steps were (a) introduction of the AcO-12 group and the C-9,C-11 double bond at ring C of methyl 3beta-acetoxyolean-12-en-28-oate (8) to afford the diene, methyl 3,12-diacetoxyolean-9(11),12-dien-28-oate (11); (b) photolytic cleavage of the C-8,C-14 bond in the diene to give an acetoxy-substituted
开发了一种新颖且用途广泛的方法,分别与4a-甲氧基羰基-制备反式十氢化萘酯Delta9(11)-3β-乙酰氧基香紫苏内酯(2)和Delta9(11)-3β-乙酰氧基-8-表香紫苏内酯(3)。由齐墩果酸(3beta-hydroxyolean-12-en-28-oic acid,1)制备的2,7,7-三甲基-1-氧代-顺式十氢化萘-2-烯(4)及其C-3羟基衍生物5。三个关键步骤是(a)引入AcO-12基团和3β-乙酰氧基油酸酯-12-en-28-O酸甲酯(8)的C环上的C-9,C-11双键以提供二烯,甲基3,12-二乙酰氧基油酸酯-9(11),12-二烯-28-酸酯(11); (b)光解二烯中的C-8,C-14键,得到乙酰氧基取代的三烯14;(c)用间CPBA / TsOH氧化三烯或其水解的α,β-不饱和酮产物,得到顺式和反式十氢化萘2-5。