Total Syntheses of Zaragozic Acids A and C by a Carbonyl Ylide Cycloaddition Strategy
作者:Yuuki Hirata、Seiichi Nakamura、Nobuhide Watanabe、Osamu Kataoka、Takahiro Kurosaki、Masahiro Anada、Shinji Kitagaki、Motoo Shiro、Shunichi Hashimoto
DOI:10.1002/chem.200601212
日期:2006.12.4
A carbonyl ylide cycloaddition approach to the squalene synthase inhibitors zaragozic acids A and C is described. The carbonyl ylide precursor 8 was synthesized starting from di-tert-butyl D-tartrate (47) via an eleven-step sequence involving the regioselective reduction of the mono-MPM (MPM=4-methoxybenzyl) ether 48 with LiBH4 and the diastereoselective addition of sodium tert-butyl diazoacetate to
描述了对角鲨烯合酶抑制剂泽拉果酸A和C的羰基内酯环加成方法。由D-酒石酸二叔丁酯(47)开始的十一步合成羰基叶立德前体8,该步骤涉及用LiBH4对单MPM(MPM = 4-甲氧基苄基)醚48进行区域选择性还原和非对映选择性加成的重氮乙酸叔丁酯钠制得α-酮酸酯10。在催化量的[Rh2(OAc)4]存在下,α-重氮酯8与3-丁炔-2-酮(40)反应得到所需产物。环加合物59为单个非对映异构体。烯酮59的二羟基化,随后进行顺序转化,可以构建功能齐全的2,8-二氧杂双环[3.2.1]辛烷核5。由5衍生的烯烃79是zaragozic酸A(1)和C( 2),