The synthesis of 14-membered macrocyclic ethers

As part of on ongoing study of the chemistry of macrocyclic compounds, 14-membered macrocyclic ethers with a variety of methyl substitution patterns were synthesized. The preparation of these macrocyclic ethers involved either the Baeyer-Villiger ring expansion of a cyclic ketone, or the macrolactonization of a hydroxy acid to give a lactone. The lactone carbonyl was removed either by conversion to an intermediate thionolactone obtained by reaction with Lawesson's reagent and reduction, or by direct reduction using a boron trifluoride etherate mediated sodium borohydride reaction. (C) 1999 Elsevier Science Ltd. All rights reserved.