M. Fujita et al., Solvolysis of optically active 4-methylcyclohexylidenemethyl triflate: Evidence against a primary vinyl cation as an intermediate, CHEM LETT, (8), 2001, pp. 806-807
Solvolysis of (R)-4-methylcyclohexylidenemethyl triflate in aqueous methano
l at 140 degreesC gave stereospecifically (R)-4-methyl-cycloheptanone to de
finitively rule out intermediate formation of the achiral primary vinyl cat
ion. The rearrangement must occur via concerted a-bond participation.