title: Enhanced regioselectivity of Yang photocyclization in the crystalline state.
abstract: [reaction: see text] In contrast to the solution state, where Yang photocyclization of ketones of general structure 1 leads to equal amounts of cyclobutanols 2 and 3 (by abstraction of HA and HB, respectively), irradiation in the crystalline state is much more regioselective, favoring either 2 or 3 depending on the nature of the substituent X. X-ray crystallography and molecular mechanics calculations reveal the source of this remarkable solid-state regioselectivity.
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, B.C., Canada V6T 1Z1.
authors.forename: Kodumuru
authors.initials: K
authors.lastname: Vishnumurthy
authors.forename: Eugene
authors.initials: E
authors.lastname: Cheung
authors.forename: John R
authors.initials: JR
authors.lastname: Scheffer
authors.forename: Carl
authors.initials: C
authors.lastname: Scott