A novel photochemical transformation of methyl 6-chloro-3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzoxazine-8-carboxylate to β-lactams
作者:Nobuhiro Marubayashi、Takayuki Ogawa、Takanobu Kuroita、Toshio Hamasaki、Ikuhiko Ueda
DOI:10.1016/s0040-4039(00)61319-9
日期:1992.8
A unique photoreaction of methyl 6-chloro-3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzoxazine-8-carboxylate in methanol gives four beta-lactam compounds, methyl 6-chloro-2,9-dioxo-1-methyl-1-azaspiro[3.5]nona-5,7-diene-8-carboxylate and three stereoisomers of dimethyl 3-chloro-4-(1'-methyl-2'-oxoazetidin-4'-ylidene)-2-butene-1,1-dicarboxylate.