(2S,3R,4S,5R)-Diethyl 2-(10,10-dimethyl-3,3-dioxo-3λ⁶-thia-4-azatricyclo[5.2.1.0^1,5]decan-4-ylcarbonyl)-5-phenylpyrrolidine-3,4-dicarboxylate: a novel isomorphous-by-addition compound

Abstract

The title compound, C(27)H(36)N(2)O(7)S, (I), is isomorphous by addition with the dimethyl ester analogue [Garner, Dogan, Youngs, Kennedy, Protasiewicz & Zaniewski (2001). Tetrahedron, 57, 71-85], (II), by replacing two methyl ester H atoms with two methyl groups. With the exception of the conformation of one of the ester groups, the molecules are almost superimposable. Likewise, apart from a slightly larger c axis in (I), few differences in the cell packing of (I) and (II) are found, with both dominated by the same C-H...O hydrogen bonds. Full synthetic and spectroscopic details of (I) are given. The molecular synthesis is important as an example of chiral auxiliary-assisted 1,3-dipolar cycloaddition of an azomethine ylid.

`Segmented' crystals solved using synchrotron radiation: (2S,3R,4S,5R)-4-(10,10-dimethyl-3,3-dioxo-3λ6-thia-4-azatricyclo[5.2.1.01,5]decan-4-ylcarbonyl)-2,6-diphenylperhydropyrrolo[3,4-c]pyrrole-1,3-dione

“…The title compound, (I), originated from a continuing research programme designed to explore preparative routes to chiral pyrrolidine scaffolds. The previously used synthetic route to (I) was employed (Gainsford et al, 2009), with the 1,3-dipolar cycloaddition carried out with N-phenylmaleimide and benzaldehyde in the presence of silver acetate. This structural study was undertaken to confirm the stereochemistry.…”

“…Selected dimensions are given in Table 1, and comparisons given in Table 3 with two related structures isomorphous by addition, viz. the diethyl and dimethyl ester analogues (II) [Cambridge Structural Database (CSD, Version 5.30, with May 2009 updates;Allen, 2002) refcode MOLGAW; Gainsford et al, 2009] and (III) (CSD refcode MIPPOQ; Garner et al, 2001), respectively. The bond length internal self-consistency raised an issue when it was observed that the S O bond distances [average 1.440 (3) Å ] are significantly longer than those in other reported 4-(10,10-dimethyl-3,3-dioxo-3 6 -thia-4-azatricyclo[5.2.1.0 1,5 ]decane-4-carbonyl structures, where the mean for 24 values in the CSD is 1.421 (1) Å .…”

“…Experimental 2-Amino-1-(10,10-dimethyl-3,3-dioxo-3 6 -thia-4-azatricyclo-[5.2.1.0 1,5 ]dec-4-yl)ethanone (185 mg, 680 mmol) was treated with benzaldehyde (69.0 ml, 680 mmol), N-phenylmaleimide (353 ml, 2.04 mmol) and silver acetate (5.70 mg, 34.0 mmol) in tetrahydrofuran (2.00 ml), as described previously by Gainsford et al (2009), to give the title compound (250 mg, 69%) as an off-white solid (m.p.…”