Complete sets of monosubstituted cyclomaltohexaoses (alpha-cyclodextrins) as precursors for further synthesis
2011
Abstract
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 2I-O-, 3I-O- and 6I-O-alkylated a-CDs in up to 27% yields. Ozonolysis or oxidative cleavage of peracetylated allyl or cinnamyl derivatives resulted in a complete set of peracetylated 2I-O-, 3I-O- and 6I-Oformylmethyl or carboxymethyl derivatives that are useful precursors for preparation of regioselectively monosubstituted derivatives of alpha-CD.
Moreover, a quick method to recognize single 2I-O-, 3I-O- and 6I-Omonosubstituted peracetylated CDs from one another using only their 1H NMR spectra has been proposed.