The structure of an achiral ester-lactone, C20H14O4 (1), which crystal
lizes spontaneously in space group P2(1)2(1)2(1), has been determined.
Solid-state photolysis gives two products, one of which is produced a
s a racemate, while the other is formed in near-quantitative enantiome
ric excess; the optical activity of the latter product probably result
s from intermolecular steric effects.