cis-1-Ethyl-4,4,6,8-tetra-methyl-2-tosyl-2,3,3a,4,6,7,8,9-octa-hydro-1H-pyrrolo[3',4':3,4]pyrano[6,5-d]pyrimidine-7,9-dione.

In the title compound, C(22)H(29)N(3)O(5)S, the pyrrolidine ring is cis-fused to the dihydro-pyran ring. The pyrrolidine and dihydro-pyran rings adopt twist and half-chair conformations, respectively. The mol-ecule is in a folded conformation; the sulfonyl-bound benzene ring lies over the pyrimidine-dione ring, with a weak π-π inter-action [centroid-centroid distance = 3.6147 (4) Å]. A weak intra-molecular C-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked into a three-dimensional network by C-H⋯O hydrogen bonds.