2-Halo-2-cyclohexenols from 6,6-Dihalobicyclo-[3.1.0]hexanes and Dimethyl Sulfoxide. Studies towards a Non-basic Hydroxide Equivalent.
作者:Ludger A. Wessjohann、Andrea Mühlbauer、Udo Sinks、Frode Rise、Michael P. Hartshorn、Manuela Merchán、Ward T. Robinson、Björn O. Roos、Claire Vallance、Bryan R. Wood
DOI:10.3891/acta.chem.scand.51-1112
日期:——
A practical, high yielding, cheap and mild method for the synthesis of 2-halo-2-cycloalkenols, especially 2-bromo-2-cyclohexenol, is reported. Direct conversion from a variety of thermally labile n,n-dihalobicyclo[n-3.1.0]alkanes to 2-halo-2-cycloalkenols can be achieved without using silver salts by simple heating in DMSO. The intermediate 1,n-dihalocycloalkenes immediately undergo indirect allylic substitution with DMSO to yield the corresponding halocycloalkenols. A possible mechanism for the substitution step comprises nucleophilic attack by DMSO followed by a Pummerer rearrangement and hydrolytic decomposition. Kinetic and mechanistic experiments to verify the course of the reaction are presented.