Acylated methyl xylopyranosides

Figure 24 Regioselective saponification of acylated methyl xylopyranosides, catalyzed by esterase.

An interesting observation was made by Ferrier and coworkers61 during the acylation of 2,4-boronic esters of methyl a- and /3-d-xylopyranosides, in both of which the pyranoid ring must be in the C.,(d) conformation, and the 3-hydroxyl group must be axially attached. On treatment with benzoyl chloride in pyridine, the a-d-xyloside derivative gave 37% of the 3-benzoate and 19% of unreacted starting-material, but the /3-D-xyloside derivative yielded... 

Fig. 30.—Acylation reactions on dibutylstannylene acetals of 4-O-substituted methyl /3-d-xylopyranosides.132...

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