Synthesis and spectroscopic characterisation of lipophilic octylated α-, β- and γ-cyclodextrin derivatives

Abstract

The octylation of α-, β- and γ-cyclodextrin may be undertaken in two steps: reaction with octyl bromide (NaOH–Me₂SO) gives relatively monodisperse 2,6-di-O-alkylated material and further reaction (NaH–THF) with octyl bromide yields incompletely octylated products. Complete alkylation may be achieved with KH–18-crown-6–THF. Quantification of the degree of octylation was achieved directly by electrospray mass spectrometry and ¹³C NMR analysis of methylated analogues and also by GC–MS analysis of reductively depolymerised samples. Assignment of the ¹H and ¹³C NMR spectra of selected derivatives has been carried out.