1. (4S)-4-Benzyl-N-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]sulfon-yl}-2-oxo-1,3-oxazolidine-3-carboxamide
Malika Berredjem, Assia Allaoui, Amani Direm, Noureddine Aouf, Nourredine Benali-Cherif Acta Crystallogr Sect E Struct Rep Online. 2010 Jun 9;66(Pt 7):o1611-2. doi: 10.1107/S1600536810020866.
The title compound, C(21)H(21)N(3)O(7)S, contains an oxazolidinone ring and a sulfonamide group, both characteristic for biologically and pharrmaceutically active compounds. Both stereogenic centres reveal an S absolute configuration. The two oxazolidinone rings are in an envelope conformation with the methyl-ene carbon flap atoms deviating by 0.428 (1) and 0.364 (2) Å from the best least-square planes formed by the four other ring atoms. An intra-molecular N-H⋯O hydrogen bond contributes to the folded conformation of the mol-ecule. In the crystal, weak inter-molecular C-H⋯O inter-actions connect the mol-ecules into helices along the the twofold screw axes.
2. (1S,3S,4S)-tert-Butyl N-[1-benzyl-3-hydr-oxy-5-phenyl-4-(picolinamido)pent-yl]carbamate
Jian-Feng Zheng, Su-Yu Huang, Jian-Nan Guo, Yu Zhang, Li-Ren Jin Acta Crystallogr Sect E Struct Rep Online. 2008 Jun 28;64(Pt 7):o1362. doi: 10.1107/S1600536808018965.
The title compound, C(29)H(35)N(3)O(4), was obtained by the reaction of (2S,4S,5S)-tert-butyl N-(4-amino-1-benzyl-3-hydr-oxy-5-phenyl-pent-yl)carbamate and picolinic acid using oxalyl chloride as a chlorinating reagent to activate the carboxyl group. In the crystal structure there are two mol-ecules in the asymmetric unit, which are aligned edge-to-face. In one mol-ecule, the pyridyl ring forms a dihedral angle of 22.0 (1)° with the phenyl ring of the terminal benzyl group and 14.3 (1)° with the other phenyl ring; in the other mol-ecule, the corresponding angles are 12.1 (1) and 10.6 (1)°, respectively. The packing is stabilized by inter-molecular hydrogen bonds and C-H⋯π inter-actions.
3. tert-Butyl N-benzyl-N-[4-(4-fluoro-benzoyl-meth-yl)-2-pyrid-yl]carbamate
Pierre Koch, Dieter Schollmeyer, Stefan Laufer Acta Crystallogr Sect E Struct Rep Online. 2008 Oct 31;64(Pt 11):o2221. doi: 10.1107/S160053680803448X.
In the crystal structure of the title compound, C(25)H(25)FN(2)O(3), the pyridine ring makes dihedral angles of 75.1 (3), 39.4 (3) and 74.6 (3)° with the phenyl ring, the carbamate plane and the 4-fluoro-phenyl ring, respectively. The phenyl ring makes dihedral angles of 77.2 (3) and 23.6 (3)° with the carbamate plane and the 4-fluoro-phenyl ring, respectively. The 4-fluoro-phenyl ring is perpendicular to the carbamate plane, the dihedral angle between them being 89.5 (3)°.
