Reaction of 2-acyloxymethyl or 2-acylaminomethyl-1, 1-dibromocycloprap
anes with methyllithium at -90 degrees C leads to selective bromine-li
thium exchange and intramolecular cyclisation to give a 1-bromo-3-oxa-
or 1-broma-3-oxa-bicyclo[3. 1.0]hexan-2-ol. (C) 1998 Elsevier Science
Ltd. All rights reserved.