ISSN:
0170-2041
Keywords:
Trifluoromethanesulfonates, secondary alkyl, as alkylating agents
;
Disaccharides, synthesis of (1→3)- and (1→4)-connected
;
Carbohydrates
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Base-promoted reaction of tetra-O-benzyl-glucose 1a with secondary alkyl trifluoromethanesulfonates 2 and 3 in toluene provides in the presence of 15-crown-5 preferentially β-glycosides 2aβ and 3aβ, respectively, in high yields. For reactions carried out at lower temperatures and with trifluoromethanesulfonates derived from secondary hydroxy groups of sugars aprotic dipolar solvents (HMPT/DMF, HMPT/THF) are required. Thus, treatment of 1-O-unprotected hexoses 1a-e with trifluoromethanesulfonates 4, 6, and 7 affords the corresponding (1→4)-connected disaccharides 4a-e and the (1→3)-connected disaccharides 6b and 7b, respectively, in high yields. Under these conditions the α:β ratio of the products resembled the anomeric ratio of the starting material.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199219920165
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