Eine ungewöhnliche Chlorwasserstoff‐Abspaltung: <i>syn</i>‐Eliminierung aus einem sterisch behinderten, aber freidrehbaren Halogenkohlenwasserstoff

Abstract

An Unusual Dehydrochlorination: syn ‐Elimination from a Sterically Hindered, but Free Rotating Halogenated Hydrocarbon Depending on the solvent, the meso ‐3, 4‐dichloro‐2,2,5,5‐tetramethylhexane undergoes base‐promoted dehydrochlorination in a syn ‐ or anti ‐periplanar manner, thus affording ( Z )‐3‐chloro‐2,2,5,5‐tetramethyl‐3‐hexene and the thermodynamically less stable ( E )‐isomer, respectively. Alcoholate aggregates of different size (presumably, dimers and trimers or tetramers) are alternatively involved in these stereochemically distinct conversions, at least when potassium t ‐butoxide in t ‐butyl alcohol or tetrahydrofuran serves as a base/solvent system.