4-Hydr-oxy-5-(4-methoxy-phen-yl)pyrrolidin-2-one.

In the title compound, C(11)H(13)NO(3), the pyrrolidin-2-one ring is in an envelope conformation with the hydroxyl and 4-methoxy-phenyl substituents mutually cis. The methoxy group is slighty twisted away from the mean plane of the attached benzene ring. The mol-ecules are arranged into screw chains along the c axis. These chains are inter-connected via inter-molecular O-H⋯O and N-H⋯O hydrogen bonds into sheets parallel to the ac plane. The crystal structure is further stabilized by weak inter-molecular C-H⋯O and C-H⋯π inter-actions.

tert-Butyl 5-(4-methoxy-phen-yl)-1-methyl-2-oxopyrrolidin-3-yl carbonate.

In the title compound, C(17)H(23)NO(5), the pyrrolidinone ring is in an envelope conformation. The tert-butyl carbonate and 4-methoxy-phenyl groups are arranged on the same side of the pyrrolidinone ring. The meth-oxy group is coplanar with the attached benzene ring. The mol-ecules are linked into chains along the b axis via C-H⋯O hydrogen bonds.

Methyl 2-{[(4-hydroxy-phen-yl)(methoxy-carbon-yl)meth-yl]amino-carbon-yl}ethano-ate hemihydrate.

In the structure of the title compound, C(13)H(15)NO(6)·0.5H(2)O, the water O atom lies on a twofold rotation axis. The methoxy-carbonyl-methyl and amino groups are essentially coplanar and the methoxy-carbonyl-methyl group makes a dihedral angle of 79.73 (10)° with the mean plane of the hydroxy-phenyl ring. The amino and methoxy-carbonyl-methyl groups are involved in an intra-molecular N-H⋯O hydrogen bond which generates an S(5) ring motif. In the crystal structure, mol-ecules are linked via N-H⋯O and O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions into a two-dimensional network parallel to the (01) plane. The crystal structure is further stabilized by C-H⋯π inter-actions.

Short and versatile route to a key intermediate for lactacystin synthesis.

[reaction: see text] A key intermediate 14 for the synthesis of lactacystin 1 has been constructed in four steps and 33% overall yield. The key steps involve cyclization of a suitably functionalized glutamic acid derivative and concomitant alkylation of the resulting beta,beta-diketoester system, C-acylation of the cyclic alpha-amidoketone 9, and decarboxylbenzylation of 12. Alkylation of a related beta,beta-diketoester 5 was additionally achieved with several electrophiles.