| Abstract
| - trans-2-Phenyltetrahydrothiophenium 1-methylide (trans-3), which is generated by fluoride ion-induced desilylation of trans-2-phenyl-1-[(trimethylsilyl)methyl]tetrahydrothiophenium salt (trans-2), gave a mixture of 1,4,5,10a-tetrahydro-3H-2-benzothiocine (4) ([2,3]sigmatropic rearrangementproduct) and 4-methylsulfanyl-1-phenyl-1-butene (5) (Hofmann elimination product). Ylide trans-3cannot undergo [2,3]sigmatropic rearrangement because the ylide-carbon is too far from the phenylgroup, and trans-3 would instead isomerize to cis-3. In this paper, we discuss the mechanism ofthe isomerization of trans-3 to cis-3.
|
