T. Keumi, K. Matsuura, N. Nakayama
Jan 15, 1993
Citations
0
Influential Citations
8
Citations
Journal
Tetrahedron
Abstract
Abstract α-Bromoacylpolymethylbenzenes 2a-m react with fuming nitric acid in acetic anhydride to give 2-(nitromethyl)-(α-bromoacyl)polymethylbenzenes 3a-m in good isolated yields. Compounds 3a-j undergo the intramolecular nucleophilic substitution/cyclization in the presence of 1 equiv. of base either in benzene or N,N -dimethylformamide (DMF) to provide the corresponding substituted 3-nitroindan-1-ones 4a-j in quantitative yields as mixtures of diastereomers ( cis and trans ). The cis/trans ratios of 4 vary with the steric factor and the nature of solvent: cis trans in benzene, whereas cis > trans in DMF. On the contrary, 3-unsubstituted 2-nitromethyl compounds 3k-m afford 3,2-benzoxazepin-5(4 H )-ones 7k-m under the same reaction condition. On the other hand, the reactions of 3a-j in the presence of 2 equiv. of base give the substituted inden-1-ones 5 in satisfactory isolated yields.