title: [(3aS,5aR,8aR,8bS)-2,2,7,7-Tetra-methyl-tetra-hydro-3aH-bis-[1,3]dioxolo[4,5-b:4',5'-d]pyran-3a-yl]methyl (R)-N-(1-phenyl-eth-yl)sulfamate.
abstract: In the title compound, C(20)H(29)NO(8)S, the two five-membered rings adopt envelope conformations (with an O atom at the flap in each case), while the six-membered pyran ring displays a twist-boat conformation. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into a supra-molecular chain running along the a axis.
authors.affiliation: School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Mail Box 40, 103 Wenhua Road, Shenhe District, Shenyang 110016,  People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xie
authors.forename: Si-Si
authors.initials: SS
authors.lastname: Shen
authors.forename: Bao-Feng
authors.initials: BF
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Sha