Jian-Feng Zheng

(1S,3S,4S)-tert-Butyl N-[1-benzyl-3-hydr­oxy-5-phenyl-4-(picolinamido)pent­yl]carbamate

The title compound, C29H35N3O4, was obtained by the reaction of (2S,4S,5S)-tert-butyl N-(4-amino-1-benzyl-3-hydroxy-5-phenylpentyl)carbamate and picolinic acid using oxalyl chloride as a chlorinating reagent to activate the carboxyl group. In the crystal structure there are two molecules in the asymmetric unit, which are aligned edge-to-face. In one molecule, the pyridyl ring forms a dihedral angle of 22.0u2005(1)° with the phenyl ring of the terminal benzyl group and 14.3u2005(1)° with the other phenyl ring; in the other molecule, the corresponding angles are 12.1u2005(1) and 10.6u2005(1)°, respectively. The packing is stabilized by intermolecular hydrogen bonds and C—H⋯π interactions.

(3S)-4-[(1S)-1-(Dibenzyl­amino)-2-phenyl­ethyl]-1,3,2-dioxathiane

The title compound, C25H27NO3S, was obtained as the major product from the reaction of (3S,4S)-4-(dibenzylxadamino)-5-phenylxadpentane-1,3-diol and sulfuryl dichloride. The molxadecular packing in the crystal is stabilized by weak interxadmolecular interxadactions and van der Waals forces.

(3S,4S)-1-Benzhydryl-4-(cyclopropylcarbonyl)-3-[(1R)-1-hydroxyethyl]azetidin-2-one

The title compound, C22H23NO3, was obtained by the reaction of (2R,3R)-N-benzhydryl-N-(2-cycloxadpropyl-2-oxoethxadyl)-2,3-epoxyxadbutyramide with Lithium bis(trimethylsilyl)amide in tetraxadhydroxadfuran solution. The absolute configuration has been assigned by reference to an unchanging chiral centre in the synthetic procedure. The molxadecular packing is stabilized by interxadmolecular O—H⋯O and C—H⋯O hydrogen bonds.

(3S, 4S)-tert-butyl 4-amino-3-hydroxy-5-phenyl-pentanoate

The title compound, (I), which belongs to the class of -amino alcohols, is a key intermediate used to synthesize chiral ligands, such as bis(oxazoline) ligands, for asymmetric catalysts. The majority of the syntheses of these ligands have followed a general synthetic route in which oxalic acid or substituted malonic acids were first condensed with the corresponding optically active -amino alcohols to form the bis(hydroxy)amide derivatives. The hydoxy groups in the bis(hydroxy)amide were then activated and the resulting intermediate was cyclized to provide the bis(oxazoline) ligands (Ghosh et al., 1998).

(Z)-5-amino-2-dibenzylamino-1-phenyl-6-(2-pyridyl)hex-4-en-3-one

The title compound, C31H31N3O, was obtained by the reaction of 4-dibenzylxadamino-3-oxo-5-phenylxadpentaxadnenitrile with 2-methylxadpyridinylmagnesium chloride. The crystal structure involves interxadmolecular N—H⋯O hydrogen bonds.

(3S,4S)-tert-butyl 4-dibenzylamino-3-hydroxy-5-phenylpentanoate

The title compound, C29H35NO3, was obtained as a major product by reduction of (S)-tert-butyl 4-dibenzylxadamino-3-oxo-5-phenylxadpentaxadnoate. The molxadecular packing in the crystal structure is stabilized by weak interxadmolecular interxadactions and van der Waals forces.

(3S, 4S)-4-(Cyclopropylcarbonyl)-3- (1R)-1-hydroxyethyl azetidin-2-one

The crystal structure of the title compound, C9H13NO3, is stabilized by interxadmolecular O—H⋯O and N—H⋯O hydrogen bonds, leading to a two-dimensional network extending parallel to the (001) plane. The absolute configuration has been assigned by reference to the chiral hydrxadoxy C atom, which remains unchanged during the synthetic procedure.