title: (Z)-1,3,4a-Trimethyl-5,5-diphenyl-6-oxa-1,3-diaza-bicyclo-[4.2.0]octane-2,4-dione.
abstract: The title compound, C(20)H(20)N(2)O(3), is a head-to-tail oxetane, one of the regioisomers obtained by the the Paternó-Büchi reaction of 1,3-dimethyl-thymine with benzophenone. The oxetane ring is folded, the dihedral angle between the C-O-C and C-C-C planes being 14.4 (2)°. The dihedral angle between the two phenyl rings is 64.3 (2)°. The pyrimidine ring adopts a boat conformation. The crystal structure involves weak C-H⋯O hydrogen bonds.
authors.affiliation: School of Pharmacy, Anhui Medical University, Hefei 230032, People's Republic of China.
authors.forename: Zhi-Cai
authors.initials: ZC
authors.lastname: Lin
authors.forename: Jing-Bo
authors.initials: JB
authors.lastname: Shi
authors.forename: Wen-Jian
authors.initials: WJ
authors.lastname: Tang
authors.forename: Jun
authors.initials: J
authors.lastname: Li