The yields are nearly quantitative and only catalytic amount (0.1 mole per mole of the substrate) of cyclodextrin is required. No optical induction was observed in the products. These reactions do not take place in the absence of CD. Here, the role of CD appears to be to activate the epoxide by supramolecular catalysis through the formation of hydrogen bonds. Though these reactions are also catalysed by a-CD, p-CD is the preferred catalyst ...