Glycosides methyl, selective esterification

Tatsuta s oleandomycin synthesis is based on the construction of the aglycone by coupling of the C1-C7 (131) and Cg-Ci3 (136) segments, which are derived from L-rhamnose and (S)-( + )-methyl 3-hydroxy-2-methylpropionate, respectively, and on the stereo- and regioselective introduction of the two sugar moieties. Methods for selective esterification and for the synthesis of 2-deoxy-a-glycosides were developed in the course of the synthesis. 

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