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-dihydroxypropyl)]-beta-cyclodextrin 3 by osmium tetroxide-catalyzed dihydroxylation. A diastereomeric mixture of 3 was treated with sodium periodate followed by sodium borohydride to give heptakis[2,3,6-tri-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 was also applied to heptakis(2,6-di-O-allyl-3-O-methyl)-beta-cyclodextrin 8, heptakis(2,3-di-O-allyl-6-O-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. All products were proved to be chemically uniform.
Kraus
T
T
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
Budĕsínský
M
M
Závada
J
J
D003505:Cyclodextrins / Q000138:chemical synthesis* / Q000737:chemistry; D005503:Food Additives / Q000138:chemical synthesis* / Q000737:chemistry; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D005503:Food Additives; D047392:beta-Cyclodextrins; C031215:betadex