4,4,6,8-Tetramethyl-2-tosylpyrrolo[3,4-c]pyrano[6,5-b]pyrimidine-7,9-dione

Abstract

In the title compound, C20H25N3O5S, the pyrrolidine ring is trans-fused to the dihydropyran ring. The pyrrolidine ring adopts a twist conformation and the dihydropyran ring is in an envelope conformation. The tosyl group is attached to the pyrrolidine ring in a biaxial position and its benzene ring forms a dihedral angle of 85.61 (4)° with the pyrimidine ring. The crystal packing shows that the molecules are linked into a three-dimensional framework through C—H...O hydrogen bonds.

cis-1-Ethyl-4,4,6,8-tetramethyl-2-tosyl-2,3,3a,4,6,7,8,9-octahydro-1H-pyrrolo[3′,4′:3,4]pyrano[6,5-d]pyrimidine-7,9-dione

“…E65, o1862-o1863 [doi:10.1107/S1600536809026361] cis-1- 4,6,3,3a,4,6,7,8,4′:3,4] Pyranopyrimidine derivatives exhibit antiviral (Shamroukh et al, 2007) and antimicrobial activities (Bedair et al, 2000(Bedair et al, , 2001Eid et al, 2004;Abdel Fattah et al, 2004). Previously, we have reported the crystal structure of trans-1- ethyl-4,4,6,8-tetramethyl-2-tosyl-2,3,3a,4,6,7,8,9-octahydro-1H-pyrrolo[3,4-c]pyrano[6,5-d]pyrimidine-7,9-dione (Chinnakali et al, 2007). Now we report the crystal structure of the title compound, a cis isomer.…”

“…A superposition of non-H atoms in the dimethyl pyrimidine-7,9-dione unit of the cis isomer (title molecule) and molecule A of the trans isomer (Chinnakali et al, 2007) (Fig. 2) shows that the overall conformations of these isomers are different.…”

1-Benzyl-6,8-dimethyl-4-phenyl-2-tosyl-1,2,3,3a,4,6,7,8,9,9b-decahydropyrrolo[3,4-c]pyrano[6,5-d]pyrimidine-7,9-dione

“…For the biological activity of pyranopyrimidine derivatives, see: Abdel Fattah et al (2004); Bedair et al (2000Bedair et al ( , 2001; Bruno et al (2000); Eid et al (2004); Shamroukh et al (2007). For a related structure, see: Chinnakali et al (2007). For ring puckering parameters, see: Cremer & Pople (1975) and for asymmetry parameters, see: Duax et al (1976).…”

trans-1-Ethyl-4,4,10-trimethyl-2-tosyl-1,2,3,3a,4,11b-hexahydro-11H-pyrrolo[3,4-c]pyrano[5,6-c]quinolin-11-one

“…For the cis-isomer, see: Chinnakali et al (2007). For ring puckering parameters, see: Cremer & Pople (1975).…”

“…In the cis-isomer, the dihydropyran ring is in a half-chair conformation. In both molecules, the sulfonyl group has distorted tetrahedral geometry [O2A-S1A-O1A = 120.04 (11)° and O2B-S1B-O1B = 120.47 A superposition of the non-H atoms in the quinolinone ring systems of molecule A or B and cis-isomer (Chinnakali et al, 2007) (Fig. 2) shows that the overall conformations of the cis and trans isomers are different.…”