Stereoselective Double Alkylation of the Acetoacetate Ester α-Carbon on a <scp>d</scp>-Glucose-Derived Template: Application to the Synthesis of Enantiopure Cycloalkenones Bearing an Asymmetric Quaternary Carbon
作者:Kin-ichi Tadano、Ikuko Kozawa、Yoko Akashi、Kumiko Takiguchi、Daisuke Sasaki、Daisuke Sawamoto、Ken-ichi Takao
DOI:10.1055/s-2007-967934
日期:2007.2
previously developed D-glucose derivative, i.e., methyl 6-deoxy-2,3-di-O-(tert-butyldimethylsilyl)-a-D-glucopyranoside, served as a significant stereocontrolling element for the diastereoselective alkylation of the α-carbon in its acetoacetate at C-4 with two types of alkyl halides. The thus obtained doubly alkylated acetoacetate moiety bearing both methyl and allyl groups was efficiently converted into
先前开发的 D-葡萄糖衍生物,即甲基 6-脱氧-2,3-二-O-(叔丁基二甲基甲硅烷基)-aD-吡喃葡萄糖苷,作为重要的立体控制元件,用于其 α-碳的非对映选择性烷基化。乙酰乙酸在 C-4 与两种类型的烷基卤化物。如此获得的带有甲基和烯丙基的双烷基化乙酰乙酸酯部分通过分子内醇醛策略有效地转化为官能化的 cycloalk-2-en-1-one 衍生物。此外,环烯酮的合成效用通过对如此获得的环戊烯酮衍生物的1,4-加成来举例说明。