Complete sets of monosubstituted cyclomaltohexaoses (α-cyclodextrins) as precursors for further synthesis

Alkylation of cyclomaltohexaose (alpha-cyclodextrin, alpha-CD) with allyl or cinnamyl bromide, followed by peracetylation of remaining hydroxyl groups and separation of isomers, resulted in the set of peracetylated 2(1)-O-, 3(1)-O- and 6(1)-O-alkylated alpha-CDs in up to 27% yields. Ozonolysis or oxidative cleavage of peracetylated allyl or cinnamyl derivatives resulted in a complete set of peracetylated 2(1)-O-, 3(1)-O- and 6(1)-O-formylmethyl or carboxymethyl derivatives that are useful precursors for preparation of regioselectively monosubstituted derivatives of alpha-CD. Moreover, a quick method to recognize single 2(1)-O-, 3(1)-O- and 6(1)-O-monosubstituted peracetylated CDs from one another using only their H-1 NMR spectra has been proposed. (C) 2011 Elsevier Ltd. All rights reserved.