Ring opening transesterification polymerization of lactones derived from menthone and carvomenthone was used to synthesize polyols for polyurethane film formulations. The polyols were synthesized at 140°C using tin(ii) octoate as catalyst, diethanolamine as trifunctional initiator, and with ratios of lactone:initiator of 9:1 or 18:1. Polyol structural features were deduced by comparison of NMR spectral data with those of simple model amide/esters of the initiator. Films were formulated from the renewable polyols, diphenylmethane diisocyanate [or poly(diphenylmethane diisocyanate)], and diethylene glycol. Thermal and mechanical properties of these polyurethane films were measured, demonstrating their potential utility as biobased thermosets for rigid or flexible foams.