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We and others have demonstrated the utility of the permanganate-promoted oxidative cyclization of 1,5-dienes for synthesis of structural fragments found in oxygenated natural productsla'b•2 and materials of medicinal importance.3 In the standard implementation of this reaction, a structurally complex product possessing four new tetrahedral stereocenters is created stereospecifically from a simple achiral diene precursor in a single transformation. Of course under these circumstances racemic

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065ChemInform Abstract The oxidative cyclization of the enantiomerically enriched dienoate (I) functionalized with a chiral auxiliary gives products (II) + (III) with relatively low stereodifferentiation. Subsequent removal of the auxiliary provides the esters (V) or (VI). In contrast, high stereoselectivities are found when the bornane-10,2-sultam system is used as the chiral auxiliary. Thus, a 9:1 mixture of (IIa) and (IIb) is initially obtained from the compound (V), and the diol (IVa) can be subsequently isolated as the major product. In addition, the compound (VI) can be transformed to the ester (VII) using this methodology.

AnEfficient Asymmetric Synthesis of (3S)-3-Amino-1-(4cyanophenyl)-2-oxopyrrolidine Hydrochloride Salt.-Coupling of bromide (II) with nitrile (III) and subsequent cyclization gives the lactam ring of the title compound. Displacement of the bromide in intermediate (IV) by treatment with excess NH 4 OH and work-up of the racemic amine with (R)-mandelic acid (V) leads to isolation of the racemic (R)-mandelic acid salt (VI). The optically pure title compound is then obtained through the dynamic resolution of amine (VI) in the presence of a catalytic amount of salicyl aldehyde and (R)-mandelic acid. -(COLSON, P.-J.; PRZYBYLA, C. A.; WISE, B. E.; BABIAK, K. A.; SEANEY, L. M.; KORTE, D. E.; Tetrahedron: Asymmetry 9 (1998) 15, 2587-2593; Monsato Life Sci., Searle, Synth. Dev., Skokie, IL 60077, USA; EN)