2 ',3 '-Didehydro-3 '-deoxythymidine N-methyl-2-pyrrolidone solvate (D4T center dot NMPO)

The title compound, 1-(2',3'-dideoxy-beta-D-glycero-pent-2-enofuranosyl)thy mine 1-methyl-2-pyrrolidone solvate, C10H12 N2O4. C5H9NO, is an NMPO solvat e of the anti-AIDS agent D4T. In its crystal structure, both the pyrimidine and the furanose rings are planar and approximately perpendicular [82.1 (4 )degrees]. The value of the torsion angle defining the orientation of the t hymine with respect to the joined furane, chi = -100.8 (4)degrees, and that of the torsion angle giving the orientation of the hydroxyl group linked t o the furane ring, = 52.9 (5)degrees, show that the glycosylic link adopts the so-called high-anti conformation and the 5'-hydroxyl group is in the +s c position. The NMPO solvate is linked to the nucleoside through a fairly s trong hydrogen bond.