Observations on the Preparation of β-Lactose Octaacetate

Attempts to substantially increase the relative proportion of β-lactose octaacetate in products of acetylation of α-lactose monohydrate using various acetylation protocols failed. Nevertheless, the revised protocol for isolation and crystallization, based on the classical work by Hudson and Johnson, rendered preparation of β-lactose octaacetate less labor intensive. It is proposed that the melting point and [α]D value are not reliable criteria of purity of β-lactose octaacetate, which can be confidently determined by 1H NMR spectroscopy.