The Michael Reaction of Silyl Enol Ethers with α,β-Unsaturated Eetones and Acetals in the Presence of Titanium Tetraalkoxide and Titanium Tetrachloride
作者:Koichi Narasaka、Kenso Soai、Yukiko Aikawa、Teruaki Mukaiyama
DOI:10.1246/bcsj.49.779
日期:1976.3
Silyl enol ethers react with α,β-unsaturated ketones and esters in the presence of TiCl4 or in the coexistence of TiCl4 and Ti(Oi-Pr)4 to give 1,5-dicarbonyl compounds in good yields. The reactions of acetals derived from α,β-unsaturated ketones with silyl enol ethers in the coexistence of TiCl4 and Ti(Oi-Pr)4, followed by successive addition of 1,2-ethanedithiol, give the Michael products, δ-keto
在 TiCl4 存在下或在 TiCl4 和 Ti(Oi-Pr)4 共存下,甲硅烷基烯醇醚与 α,β-不饱和酮和酯反应,以良好的收率得到 1,5-二羰基化合物。在 TiCl4 和 Ti(Oi-Pr)4 共存下,α,β-不饱和酮衍生的缩醛与甲硅烷基烯醇醚反应,然后连续加入 1,2-乙二硫醇,得到迈克尔产物,δ-酮乙烯硫缩醛,收率良好。当上述实验中使用Ti(OCEt3)4代替Ti(Oi-Pr)4时,甲硅烷基烯醇醚与α,β-不饱和醛衍生的缩醛反应也得到迈克尔产物,并成功应用于简单合成二氢玫瑰氧化物。