The synthesis of 14-membered macrocyclic ethers

As part of an 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.