New Derivatives of Levoglucosan by Tandem Epoxide Allyl Alcohol Rearrangement‐Cuprate Cross‐Coupling

Abstract

Abstract The alkylated allyl alcohols 6a , 7 , and 8 (R = Me, Et, n Bu) were formed in the reaction of the Černý epoxide 3 with the Cyano–Gilman cuprates. The one‐pot reaction was initiated by base‐catalyzed epoxide allyl alcohol rearrangement to compound 5 , followed by unprecedented vinyl tosylate cross‐coupling with the cuprates, to form the alkylation products 6a , 7 , and 8 . The allyl alcohol 6a was transformed into a number of new branched 1,6‐anhydro sugars in series of highly stereoselective reactions. The products are stereochemically complementary to most known Černý epoxide derivatives and may be useful as chiral building blocks for polypropionate‐derived natural products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)