inhibitors of the biosynthesis of cholesterol, were synthesized in a convergent and perfectly stereoselective manner. In the key step, bromobutenolide 6 (obtained from levulinic acid in two steps) was coupled with either of the novel bis(stannanes) trans,cis,trans-35 or trans,trans,trans-35 [each accessible from 3-(tributylstannyl)allyl alcohol (17) in four steps], giving gamma-alkylidenebutenolide trans
以会聚且完全立体选择性的方式合成了作为
胆固醇生物合成
抑制剂的标题化合物2和3。在关键步骤中,将
溴丁烯内酯6(分两步从
乙酰丙酸中获得)与新型双(stannanes)反式,顺式,反式-35或反式,反式,反式-反式35偶联[每个都可从3-(三
丁基锡烷基)获得醇)(17个步骤,共分四个步骤),得到γ-亚烷基亚
丁烯内酯trans,trans,trans-32。该化合物与
碘二炔42或
溴代二炔酸酯44偶合,分别产生二氢干蛋白(2)和干蛋白酸的(三甲基甲
硅烷基乙基)酯45。后者的脱保护首次提供了完全合成的木
藻酸(3)。