Carbonyl oxides, derived by ozonolysis of vinyl ethers, readily undergo [3 + 3] cycloaddition reactions with nitrones affording dihydro-1,2,4,5-trioxazines in fair to excellent yield. The structures of dihydro-3,5,6-triphenyl-1,2,4,5-trioxazine (5f) and dihydro-3-cyclohexyl-5-methyl-6,6-diphenyl-1,2,4,5-trioxazine (5t) were unambiguously determined by X-ray analysis. Ozonolysis of 1-cyclohexyl-2-methoxyethene in the presence of either (E)- or (Z)-a-(4-methylphenyl)-a-phenyl-N-methylnitrone gave a 1:1 mixture of two stereoisomeric cycloadducts. This result, in conjunction with the structure of the relevant 5t, suggests that the [3 + 3] cycloaddition proceeds by a stepwise mechanism. © 1992 American Chemical Society.
|Number of pages||10|
|Journal||Journal of Organic Chemistry|
|Publication status||Published - 1992|