Marjorie C. Caserio

Small-ring compounds—XXIX A reinvestigation of the solvolysis of cyclopropylcarbinyl chloride in aqueous ethanol. Isomerization of cyclopropylcarbinol

The solvolysis of cyclopropylcarbinyl chloride in 80% ethanol is attended by substantial rearrangement—not only do the solvolysis products include cyclobutyl and allylcarbinyl alcohols and ethyl ethers but cyclopropylcarbinyl chloride undergoes partial rearrangement by “internal return” to cyclobutyl and allylcarbinyl chlorides. Nuclear magnetic resonance spectroscopy has been used to demonstrate that considerable isotope-position rearrangement takes place under quite mild conditions in the reactions of deuterium-labeled cyclopropylcarbinol and cyclobutanol with thionyl chloride. Isotope-position changes have been studied in the acid-induced isomerization of cyclopropylcarbinol.

Benzyn-Zwischenprodukte in der nukleophilen aromatischen Substitution

Many substitution reactions of aromatic halides, such as amination with metallic amides in ammonia or amine solutions, high-temperature alkaline hydrolyses and arylation with phenyllithium, lead to the formation of rearrangement products as the result of a common reaction path involving unstable ‘benzyne’ intermediates. The chemical evidence in favor of this reaction mechanism is discussed as are correlations of observed product compositions and applications to practical synthetic procedures.