General approach to the synthesis of persubstituted hydrophilic and amphiphilic beta-cyclodextrin derivatives

Heptakis(2,3,6-tri-O-allyl)-beta -cyclodextrin 2 was converted to heptakis [2,3,6-tri-O-(2,3-dihydroxy-propyl)] -beta -cyclodextrin 3 by osmium tetrox ide-catalyzed dihydroxylation. A diastereomeric mixture of 3 was treated wi th sodium periodate followed by sodium borohydride to give heptakis[2,3,6-t ri-O-(2-hydroxyethyl)]-beta -cyclodextrin 5 in 86% yield. Compound 5 could be quantitatively transformed into heptakis(2,3,6-tri-O-carboxymethyl)-beta -cyclodextrin 6 by TEMPO-mediated oxidation. The same reaction sequence wa s also applied to heptakis(2,6-di-O-allyl-3-O-methyl)-beta -cyclodextrin 8, heptakis (2,3-di-O-allyl-6-0-methyl)-beta -cyclodextrin 12, and heptakis(2 ,3-di-O-allyl-6-O-butyl)-beta -cyclodextrin 16; the analogous corresponding hydroxyethyl and carboxymethyl derivatives were isolated in high yields. A ll products were proved to be chemically uniform.