In the title compound, C(17)H(20)N(2)O(2)S(2), the five-membered heterocycle exhibits an envelope conformation and the mol-ecular chirality and configuration are well preserved from l-tartaric acid. The dihedral angle between the two thio-phene rings is 17.0 (2)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯S hydrogen inter-actions, which are effective in the stabilization of the cry...

In the title compound, C(34)H(35)NO(7)S, the acenaphthyl-ene unit is essentially planar (r.m.s. deviation = 0.0335 Å). The pyrrolo-thia-zole ring system is folded about the bridging N-C bond; the thia-zolidine and pyrrolidine rings adopt S- and C-envelope conformations, respectively, with a 'butterfly' angle between the mean planes of 51.38 (10)°. The dioxolane and tetra-hydro-furan rings adopt...

During our investigation of the reduction of acrylic acid with lithium aluminum hydride, we observed several unidentified compounds. One of them seemed to be 2-vinyl1,3-dioxolane (3a), which is a widely known compound, but its formation under the reaction conditions was totally unexpected. In order to confirm the identity of the compound we attempted preparation of authentic compound of 3a from...

In the title compound, C10H14Cl3NO5, the five-membered dioxolane ring adopts an envelope conformation. The C atom at the flap, which is bonded to the hy-droxy-methyl substituent, deviates from the mean plane of other ring atoms by 0.357 (5) Å. There are two intra-molecular hydrogen bonds (O-H⋯N and N-H⋯O) between the hy-droxy and amino groups, so that O- and N-bound H atoms involved in these hy...

In the title compound, C39H38N4O8, the quinoxaline and indene subunits are essentially planar, with maximum deviations of 0.071 (2) and 0.009 (2) Å, respectively. The indeno-quinoxaline system forms a dihedral angle of 72.81 (3)° with the chromenopyrrolizine system. The two dioxolane rings, as well as the pyran ring of the chromeno group and the terminal pyrrolizine, each adopt an envelope conf...

In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetra-hydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the 'butterfly' angle between their mean planes is 62.98 (11)°. The dioxolane ring adopts a twist conformation and the tetra-hydro-furan...

3,7-Diallyl-bispidin-9-one (6) (bispidin-9-one = 3,7-diazabicyclo[3.3.1]nonan-9-one) is converted to N-unsubstituted spiro[bispidin-9,2'-[1,3]dioxolane] (12; 35%). The ketal crystallizes in the forms of anhydrous 12a and the dihydrate 12b. The molecules in anhydrous 12a are linked to each other, forming N1-H1···N2-H2···N1* hydrogen-bond chiral helices of alternating chirality. In the dihydrate ...