PHOTOCHEMICAL NITRATION BY TETRANITROMETHANE .21. THE REGIOCHEMISTRY OF NITRITO TRINITROMETHYL AND NITRO TRINITROMETHYL ADDITION TO 2,6-DIMETHYLNAPHTHALENE

The photonitration of 2,6-dimethylnaphthalene with tetranitromethane in dichloromethane at + 20-degrees-C gives mainly the adducts trans-3,7-dimethyl-2-nitro-1-trinitromethyl-1,2-dihydronaphthalene 7, the epimeric 2,6-dimethyl-l-nitro-4-trinitromethyl-1,4-dihydronaphthalenes 8 and 10, the epimeric 3,7-dimethyl-l-nitro-4-trinitromethyl-1,4-dihydronaphthalenes 9 and 12, the epimeric 2,6-dimethyl-4-trinitromethyl-1,4-dihydronaphthalen-l-ols 11 and 16, trans-3,7-dimethyl-1-trinitro-methyl-1,2-dihydronaphthalen-2-ol 15, the two regioisomeric nitro cycloadducts 13 and 14, and the hydroxy cycloadduct 17. trans-3,7-Dimethyl-2-nitro-1-trintromethyl-1,2-dihydronaphthalene 7 and trans-3,7-dimethyl-1-trinitromethyl-1,2-dihydronaphthalen-2-ol 15 undergo thermal alkene-nitro cycloaddition to give the nitro cycloadduct 14 and the hydroxy cycloadduct 17, respectively. The mode of formation of these products are discussed. X-ray crystal structures are reported for adducts 8, 10, 14 and 17.