HYPERCONJUGATION AND HOMO-HYPERCONJUGATION IN THE 1-ADAMANTYL CATION - QUALITATIVE MODELS FOR GAMMA-DEUTERIUM ISOTOPE EFFECTS

An experimental and theoretical study of the modes of stabilization of the carbocation-like transition state in the solvolysis of 1-substituted adamantyl systems is presented. Experimental determination of β- and α-deuterium isotope effects are used as a probe for hyperconjugative and homohyperconjugative stabilization. Ab initio molecular orbital theory is utilized to examine these same stabilizing influences. Our findings indicate carbon-carbon hyperconjugative stabilization to be the major mode of cation stabilization in the adamantyl system. © 1979, American Chemical Society. All rights reserved.