Improved solubility of β-cyclodextrin inclusion complexes by using liquid ammonia as a solvent and the possibility of asymmetric reduction

Dramatic improvement in the poor solubility of β-cyclodextrin (β-CD) and its inclusion complexes in water was achieved by using liquid ammonia (liq. NH3) instead of water as the solvent. Asymmetric NaBH4 reduction of the carbonyl groups of the inclusion complexes in liq. NH3 was examined in a homogeneous condition to give the corresponding alcohols with moderate chirality.