“…The IR absorptions were observed at νmax 3500, 1779, and 1732 cm -1 , suggesting the presence of hydroxy, γ-lactone, and ester groups in 1, respectively. From the 13 C NMR data (Table 1), together with DEPT and HSQC spectra, illustrated the presence of 28 carbons in 1, including five ester carbonyls (δC 171.6, OAc-16; 170.6, OAc-2; 170. as well as seven methyls, two aliphatic sp 3 methylenes, one aliphatic sp 3 methine, and one aliphatic sp 3 nonprotonated carbon. Analysis of the 1 H (Table 1), 13 C, and HSQC spectra confirmed that 1 possessed a tetrasubstituted epoxide (δC 70.…”