Abstract
The reaction of 2, 2, 6-trimethyl-1, 3-dioxin-4-one (diketene-acetone adduct) (1) with imines was investigated. Heating of the adduct 1 with N-(1-phenylethylidene) aniline (6a) gave 6-methyl-1, 2-diphenyl-4-(1H)-pyridone 7a. Similar treatment of N-benzylideneaniline (3a) gave 3, 4-dihydro-6-methyl-2, 3-diphenyl-2H-1, 3-oxazin-4-one (4a). N-Benzylidenealkylamines likewise reacted with the adduct 1 to give the corresponding 1, 3-oxazine derivative 4. Reaction of diketene with N-benzylidenealkylamines in the presence of triethylamine gave the corresponding 1, 3-oxazine along with 3-acetyl-1-alkyl-4-phenylazetidin-2-one (8).
