Skeletal rearrangement for water loss from molecular protonated ions oft-butoxycyclohexane
摘要:
AbstractIsotopic labelling and chemical substitution support the proposition that the skeletal rearrangement for water loss from molecular protonated ions of t‐butoxycyclohexane involves competition between three reaction pathways. The principal reaction pathway (83%) involves migration of the t‐butyl group to the 2‐(6‐) position of the cyclohexyl ring with reciprocal hydrogen transfer. A second reaction pathway (12%) involves ring contraction followed by reciprocal exchange of the t‐butyl group with the 2‐(5‐) hydrogen atom of the nascent cyclopentyl ring. The third reaction pathway (5%) involves rearrangement of a proton‐bound complex to permit ipso attack by isobutene. Stereospecific substitutions indicate that the principal reaction pathway is susceptible to 1,3‐diaxial interactions.
.tau.-Silicon stabilization of carbonium ions in solvolysis. 4. Solvolysis of cis- and trans-3-(trimethylsilyl)cyclohexyl and -3-tert-butylcyclohexyl p-bromobenzenesulfonates