Studies in the nature of the α,ω-rearrangement

Abstract

The conditions under which two groups X and Y, attached to carbon atoms α and ω in an organic structure, may exchange places have been investigated. The pyrolyses of halogeno-O-thiobenzoates, of bis-O-thiobenzoates, and of bis-imidates have been shown to furnish rearrangement products which can be classified under this principle. In a number of examples the mechanism of rearrangement has been shown to be intermolecular in nature and ionic in character. The ring size of the intermediate ion (5,6, but not, in general, 7) appears to provide a practical limit to the extent of these α,ω-rearrangements. The familiar diaxial–diequatorial rearrangements can be classified as the first (αβ) examples of the αω-family of rearrangements.

The potential synthetic value of the bis-imidate rearrangements is mentioned.