Deacetylnomilin monohydrate

Abstract

In the title compound (systematic name 1-hydroxy-1,2-dihydroobacunoic acid 3,4-lactone monohydrate), C26H32O8·H2O, the dihedral angles between the planes of the ester groups and the furan plane are 43.06 (12) and 56.06 (7)°, while that between the furan plane and the keto group is 58.50 (9)°. The A/B, B/C and C/D ring junctions are all trans-fused. Intermolecular O—H...O hydrogen bonds between the hydroxy and carbonyl groups and the water molecule give rise to a three-dimensional structure.