A one-pot method for the asymmetric synthesis of tert-butanesulfinyl-protected amines is described. Condensation of aryl alkyl and dialkyl ketones with tert-butanesulfinamide followed by in situ reduction with the appropriate reagent provides either diastereomer of the sulfinamide products in good yields and with diastereomeric ratios of up to 99:1.

In the first total synthesis of ent-dioxepandehydrothyrsiferol, the signature trans-anti-trans 7,7,6-fused tricyclic polyether framework was constructed in a single bromonium-initiated epoxide-opening cascade that incorporates both endo- and exo-selective epoxide openings, each directed by the substitution pattern of the epoxide (methyl groups). This study thus demonstrates the feasibility of a possible biogenesis.

Herein we describe in full our investigations leading to the first total syntheses of ent-dioxepandehydrothyrsiferol and armatol A. Discovery of a bromonium-initiated epoxide-opening cascade enabled novel tactics for constructing key fragments found in both natural products and have led us to revise the proposed biogeneses. Other common features found in the routes include convergent fragment coupling strategies to assemble the natural products’ backbones and the use of epoxide-opening cascades for rapid constructions of the fused polyether subunits. Through de novo synthesis of armatol A, we elucidate the absolute and relative configuration of this natural product.

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Nitrile formation O 0273One-Pot Microwave-Promoted Synthesis of Nitriles from Aldehydes via tert-Butanesulfinyl Imines. -Aldehydes are converted to the corresponding nitriles via sulfinamide condensation followed by imine elimination. The process tolerates various functional groups and proceeds without racemization in the case of chiral substrates. -(TANUWIDJAJA, J.; PELTIER, H. M.; LEWIS, J. C.; SCHENKEL, L. B.; ELLMAN*, J. A.; Synthesis 2007, 21, 3385-3389; Dep. Chem., Univ. Calif., Berkeley, CA 94720, USA; Eng.) -Mais 13-041