Abstract

<jats:p>An earlier study of the
relative rates of degradation of several sucrose derivatives has been refined
and extended. The results support a novel hypothesis to explain the unusual
alkali-lability of sucrose (1). In this hypothesis
the first and rate-determining step in the degradation is an SN1cB
displacement effected at the C1 anomeric centre of the glucose moiety by an
oxyanion derived from the C1' hydroxyl (10), to produce 1-(α-D-glucopyranosyl)fructose
(11). The latter is then very rapidly degraded, mainly to lactic acid. The
possibility of analogous competing displacements involving the 3' and 6'
oxyanions remains for further investigation.</jats:p>