Efficient method for the lactonization of ω-hydroxycarboxylic acids with di-2-thienyl carbonate by the promotion of catalytic amounts of DMAP and Hf(OTf)4

An efficient method for the synthesis of macrolides from omega-hydroxycarboxylic acids is established by using an equimolar amount of di-2-thienyl carbonate (2-DTC) and catalytic amounts of 4-(dimethylamino)pyridine (DMAP) and group 4 metal triflates such as hafnium(IV) trifluoromethanesulfonate (Hf(OTf)(4)).