Pergamon Tetrahedron Letters 41 (2000) 659–662 TETRAHEDRON LETTERS Reaction of 5,6-cyclic sulfates derived from glycofuranoses with bases. A one-pot synthesis of 6-deoxy-hexofuranos-5-ulose derivatives Thierry Gourlain, Anne Wadouachi * and Daniel Beaupère Laboratoire de Chimie Organique, Université de Picardie Jules Verne, 33 rue Saint-Leu 80039 Amiens, France Received 16 September 1999; accepted 12 November 1999 Abstract Methyl 2,3-O-isopropylidene-5,6-O-sulfuryl-α-D-mannofuranoside 1 reacted with nitrogen bases to give the corresponding aminosulfates. Strong bases such as sodium tert-butoxide or n-butyllithium afforded methyl 6- deoxy-2,3-O-isopropylidene-α-D-lyxo-hexofuranos-5-uloside 7. The reaction was optimized with sodium tert- butoxide and applied to three other 5,6-cyclic sulfates derived from aldofuranosides to give the corresponding keto-aldoses in good yields. © 2000 Published by Elsevier Science Ltd. All rights reserved. The cyclic sulfates of vic-diols are well known and have been used as electrophiles in a variety of nucleophilic displacement reactions. 1 Such sulfates are obtained by catalytic oxidation of cyclic sulfites with ruthenium trichloride and sodium periodate. 2 We have already reported the regioselective synthesis of 6-O-alkyl and 6-alkynyl-6-deoxy compounds via a 5,6-cyclic sulfate derived from mannofuranose. This method has been extended to pseudo-di or trisaccharides and pseudo-C-disaccharides. 3–5 More recently, it has been shown that 1,2-O-sulfuryldecane failed to generate C–C bonds with some carbon nucleophiles. For example, 1,2-O-sulfuryldecane reacted with n-butyllithium to give, unexpectedly, dodecanal in 99% yield. 6 We herein report on the reactivity of 5,6-cyclic sulfates of glycofuranoses towards various organic and inorganic bases. The results of the reaction of methyl 2,3-O-isopropylidene-5,6-O-sulfuryl-α-D-mannofuranoside 1 3 with bases are illustrated in Table 1. As expected, the use of weak bases such as pyridine (entry 1), triethylamine (entry 2) or DBU (entry 3), gave the corresponding aminosulfates 2, 7 3 8 and 4 9 in quantitative yields. Similarly, reactions with strong nitrogen bases such as sodium amide (entry 5) and LDA (entry 6) with the 5,6-cyclic sulfate 1 also gave the expected substitution products 5 10 and 6, 11 respectively (Scheme 1). * Corresponding author. Fax: +33 3 22 82 75 61; e-mail: anne.wadouachi@sc.u-picardie.fr (A. Wadouachi) 0040-4039/00/$ - see front matter © 2000 Published by Elsevier Science Ltd. All rights reserved. PII: S0040-4039(99)02158-9 tetl 16086