Synthesis of mono & disaccharide glycoside amino acid to cure cholera

Synthesis of targeted molecules which are linked galactosylated - serine 27 and theronine 28 derivatives as well as linked galactosylated - serine 29 and theronine 30 derivatives was prepared. Also successful synthesis of galabiose was achieved which further used to synthesize linked glycoside of protected serine and theronine to get proposed compound 33 and 34 with benzoyl protection on the sugar part. Other acceptor which can be used for synthesis galabiose with decrease number of bnzyl was prepared 40, 44, 47 and 51. As amino protected serine and theronine was glycosylated with appropriately protected galactose and galabiose derivatives with the carboxyl terminal of 27-30, 33 and 34 can be protected followed by deprotection of amino protection group can be further used to couple with the free carboxylic group of these 27-30, 33 and 34 as well as with different amino acid, which on finally coupled intra molecularly, deprotection of the carbohydrate protecting groups to produce pentavalent cyclic glycopeptide of galactose and galabiose as multivalent cholera inhibitor toxin.