Syntheses of Lewis Determinants and Sialyllactosamine Derivatives

61 was per-O-benzylated (benzyl bromide, sodium hydride in DMF) to afford 

62 (81%). Removal of the allyl ether protecting group of 62 was effected  

Tliioglycoside 79 may be oxidatively activated to provide a sulfoxide donor of the Le deteniiinant. In the present example, the phern l thio glycoside was hydrolyzed under catalysis by mercuiy(II) trifluoroacetate (77%) and the resulting anomeric mixture of hemiacetals O-methylated (methyl iodide, sodium 

Syntheses of sLc and Related Determinants Based on Organic-Chemical Glycosylations 

3-phenylthio or 3-phenylseleno groups for stereoselective syntheses of sialocon-jugates have been developed by Ogawa and his associates - - and by Okamoto et al. 

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