Stereocontrolled 1,3-dipolar cycloadditions using Oppolzer's camphor sultam as the chiral auxiliary for carbonyl stabilized azomethine ylides

`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

“…D = À17.9 (c 1.09, CHCl 3 ). The spectroscopic data were consistent with those previously reported by Garner et al (2001) {compound (39a) in section 3.6.3, which has the alternative name [1R-[1(3aR*,6S*,7aS*),3,3a,6a]]-hexahydro-8,8-dimethyl-1- [(hexahydro-4,6-dioxo-3,5-diphenylpyrrolo[3,4-c]pyrrol-1-yl)carbonyl]-3H-3a,6-methano-2,1-benzisothiazole 2,2-dioxide}. The crystallization solvent was dichloromethane and crystals of (I) formed from the diffusion of ether into the solution.…”

“…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 .…”

Facile Method for 1,3-Dipolar Cycloaddition Reaction of Azomethine Ylides: Highly Stereoselective Synthesis of Substituted Pyrrolidine Derivatives

“…A number of methods have been developed for the asymmetric synthesis of pyrrolidines. The formation of optically active pyrrolidines in previous work was achieved in the presence of a chiral auxiliary or a Lewis acid . The first diastereoselective 1,3‐DC reaction of chiral alkenes with azomethine ylides from Kanemasa et al was by the use of α,β‐unsaturated carbonyl compounds bearing a 2‐pyrrolidinyl chiral controller, or analogs .…”

(2S,3R,4S,5R)-Diethyl 2-(10,10-dimethyl-3,3-dioxo-3λ6-thia-4-azatricyclo[5.2.1.01,5]decan-4-ylcarbonyl)-5-phenylpyrrolidine-3,4-dicarboxylate: a novel isomorphous-by-addition compound

“…Our work sought to capitalize upon the findings of Garner and co-workers (Garner & Kaniskan, 2005;Garner et al, 2001Garner et al, , 2006 and others (Padwa et al, 1985), who demonstrated that a diastereofacial bias was indeed possible utilizing a chiral auxiliary on an ylid dipole. The synthetic route to (I) employed the glycyl sultam chiral auxiliary, (2), which was prepared from enantiomerically pure (+)-camphor 10-sulfonic acid (Davis et al, 1988;Oppolzer et al, 1989;Hoppe & Beckmann, 1979).…”

“…The asymmetric unit of (I) is shown in Fig. 1, with selected dimensions compared with the dimethyl ester analogue, (II) [Garner et al, 2001;Cambridge Structural Database (Version 5.29, with November 2007 updates;Allen, 2002) refcode MIPPOQ], in Table 2. The cell dimensions, molecular packing and alignment of (I) are closely related to those of the dimethyl analogue (Figs.…”