Towards the selective acylation of secondary hydroxyl groups of carbohydrates using oxime esters in an enzyme-catalyzed process
✍ Scribed by Rosalino Pulido; Vicente Gotor
- Book ID
- 102998610
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 967 KB
- Volume
- 252
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
A lipase from Candida antarctica was used for the regioselective acylation and alkoxycarbonylation of the primary hydroxyl group of 2-deoxy-D-arabino-hexopyranose (1) and 2-deoxy-o-lyxo-hexopyranose
(2) using oxime esters as acylating agents. Both, pyridine and 1,Cdioxane were used as solvents in the acylation process, but only 1,4-dioxane was effective for the alkyloxycarbonylation.
A lipase from Pseudomonas cepacia catalyzed also the regioselective acylation of the primary hydroxyl group of 1 and 2 when 1,4-dioxane was used as solvent. Moreover, this lipase was a suitable biocatalyst for the acylation of the secondary HO-3 of 6-O(benzyloxy)carbonyl derivatives of 2-deoxy-o-hexoses. Subsequent deprotection of the primary hydroxyl group through catalytic hydrogenation readily afforded the 3-0-acyl derivatives of 1 and 2. A study of the regioselective acylation and alkyloxycarbonylation of 1,6-anhydro-p-o-glucopyranose by the aforementioned lipase is also reported.