gem-Dimethyl olefins (III) were transformed regiospecifically to the terminal β-methallyl sulfides (IV) bearing the methoxycarbonylmethyl substituent on the sulfur atom via (A) methoxycarbonylmethanesulfenyl chloride addition followed by dehydrochlorination or (B) allylic chlorination with SO2Cl2 followed by sulfenylation with methyl thioglycolate. Treatment of the sulfides (IV) with tert-BuOK or NaH in N, N-dimethylformamide or dimethyl sulfoxide at room temperature gave stereoselectively the sulfur-free esters (V) through a novel one-pot desulfurizative [2, 3]-sigmatropic rearrangement. By utilizing this method, biologically and pharmacologically important linear degraded terpenoids, a diol component (1) of the pheromonal secretion of the queen butterfly and several ω-quinoid acids (4, n=1, 2) and (5, n=1, 2), which are metabolites of polyisoprenoidquinones, were synthesized.
gem-Dimethyl 烯烃 (III) 通过 (A) 向甲氧基羧
甲烷磺酰氯的加成反应后去
氯化,或 (B) 与 SO2Cl2 的烯丙基
氯化反应,再与甲基
硫代
甘油酸酯进行
硫烯基化反应,特异性地转化为带有甲氧基羧甲基取代基的末端 β-美沙酰
硫化物 (IV)。在室温下,用 tert-BuOK 或 NaH 处理这些
硫化物(IV)于
N,N-二甲基甲酰胺或
二甲基亚砜,得到无
硫的酯 (V),这一过程通过一种新颖的一锅式脱
硫 [2,3]-σ-转位重排实现。利用该方法,合成了
生物和药理学上重要的线性降解萜烯,蝴蝶女王的信息素分泌物中的二醇成分 (1),以及几种 ω-醌酸 (4, n=1, 2) 和 (5, n=1, 2),这些都是多
异戊二烯醌的代谢物。