A
photochemical reaction of a
β,γ-unsaturated ketone to form a saturated
α-cyclopropyl ketone.
The
rearrangement formally amounts to a 1,2-acyl shift and '
bond formation' between the former α and γ carbon atoms.
Source:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2258