Structural analogues of the calanolide anti-HIV agents. Modification of the trans-10,11-dimethyldihydropyran-12-ol ring (ring C)1. - Zembower,D.E.; Liao,S.; Flavin,M.T.; Xu,Z.Q.; Stup,T.L.; Buckheit,R.W. (J Med Chem, 1997)