Crystal structure of (+)-N-[(1R,5S,6S,9S)-5-hydroxymethyl-3,3,9-trimethyl-8-oxo-2,4,7-trioxabicyclo[4.3.0]nonan-9-yl]acetamide

In the title compound, C12H19NO6, the six-membered 1,3-dioxane ring adopts a chair-like conformation. The seat of this chair, containing two O atoms, is essentially planar, with a maximum deviation of 0.0021(12)A. The five-membered oxolane ring cis-fused to the 1,3-dioxane ring adopts an envelope form. The bridgehead C atom at the flap, which is bonded to the tetrasubstituted C atom of the oxolane ring, deviates from the mean plane of other ring atoms by 0.539(4)A. In the crystal, classical O - H⋯O and N - H⋯O hydrogen bonds link the molecules into a sheet structure enclosing an R 4 ⁴(24) graph-set motif. Weak intermolecular C - H⋯O interactions support the sheet formation.