Synthesis of Open-Chain a-Silyl Vinyl Sulfides

Synthesis of Open-Chain a-Silyl Vinyl Sulfides 

The simplest compound in this series, 1-phenylthio- 1-trimethylsilyl ethylene 45, was conveniently prepared by Magnus and co-workers either by reaction of a-lithio vinyl phenyl sulfide 46 with trimethylsilylchloride,53 or by addition of arylsulfenyl-chloride to vinyl trimethylsilane followed by elimination of hydrogen chloride54 

The presence of a substituent in the p-position of the a-silyl vinyl sulfides introduces the problem of geometry in the resulting olefins. As yet, relatively few synthetic methods for -substituted a-silyl vinyl sulfides are known and some of them afford the olefins as a mixture of E- and Z-isomers. For example, the Peterson olefination of bis(trimethylsilyl)alkylthiomethyllithium 47 with aldehydes55 and the treatment of the sulfoxides 48 with LDA and trimethylchlorosilane56 gave 

---

C. Synthesis of Open-Chain a-Silyl Vinyl Sulfides... 

---