On the regioselective acylation of 1,6-anhydro-β-D- and L-hexopyranoses catalysed by lipases: Structural bass and synthetic applications

Article abstract of DOI:10.1080/07328309808005771

With the aim of providing new methods for the regioselective protection at the 2,3 and 4 positions of monosaccharides, we have studied the acetylation of a class of rigid sugars: the 1,6-anhydro-β-D- and L-hexopyranoses (hexopyranosanes D-1 to D-5 and L-1 to L-5), using vinyl acetate as an acyl donor and two common lipases,Candida rugosa and Pseudomonas cepacia, as catalysts. Our results indicate that the relative orientation of the hydroxyls governs the regioselectivity of acetylation. In the D-series, when the 3-OH is in the axial position, acetylation occurs mainly at the 4-axial OH, while the 2-axial OH is preferred when the 4-OH is equatorial. Conversely, when the 3-OH is equatorial, a strong selectivity affects the equatorial 2-OH. Compounds of the L-series were shown to be poor substrates for the lipase Pseudomonas cepacia except for L-galactosane for which the 2-monoacetyl ester was obtained in good yield. An attempt to rationalize the results by means of molecular modelling is also made to account for the catalytic activity of the Candida rugosa lipase on hexopyranosanes 1-3.

Full text of DOI:10.1080/07328309808005771

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On the Regioselective Acylation of 1,6-
Anhydro-β-d- and l-Hexopyranoses
Catalysed by Lipases: Structural Basis
and Synthetic Applications
Nathalie Boissièere-Junot a , Charles Tellier a & Claude Rabiller a
a UPRES n° 2161 “Biocatalyse”, Faculté des Sciences et des
Techniques, 2, rue de la Houssinière, BP 92208, 44322, NANTES
cedex, 3, France Phone: 33 (0)2 40 37 31 25 Fax: 33 (0)2 40 37 31 25
E-mail:
Published online: 16 Aug 2006.
To cite this article: Nathalie Boissièere-Junot , Charles Tellier & Claude Rabiller (1998): On the
Regioselective Acylation of 1,6-Anhydro-β-d- and l-Hexopyranoses Catalysed by Lipases: Structural
Basis and Synthetic Applications, Journal of Carbohydrate Chemistry, 17:1, 99-115
To link to this article: http://dx.doi.org/10.1080/07328309808005771
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