PHOTOCHEMICAL NITRATION BY TETRANITROMETHANE .18. THE REGIOCHEMISTRY OF NITRITO TRINITROMETHYL AND NITRO TRINITROMETHYL ADDITION TO 2,3-DIMETHYLNAPHTHALENE - THERMAL 1,3-DIPOLAR ADDITIONS OF NITRO-GROUPS TO ALKENES/

The photolysis of the 2,3-dimethylnaphthalene-tetranitromethane charge -transfer complex gives 2,3-dimethyl-1-nitronaphthalene, 2,3-dimethyl- 5-nitronaphthalene and adducts: epimeric pairs of yl-1-nitro-4-trinitr omethyl-1,4-dihydronaphthalene 7 and 8, 7-dimethyl-4-trinitromethyl-1, 4-dihydronaphthalene 11 and 12, yl-1-nitro-4-trinitromethyl-1,4-dihydr onaphthalene 13 and 14, and the structurally similar yl-2-nitro-l-trin itromethyl-1,2-dihydronaphthalene 9 and 7-dimethyl-1-trinitromethyl-1, 2-dihydronaphthalene 10. At +20-degrees-C in either dichloromethane or acetonitrile the adducts 7-14 comprise some 70% of the product mixtur e, but at -20-degrees-C in either solvent the total adduct yield is re duced to ca. 31%. In adduct formation trinitromethanide ion reacts pre ferentially at C-5 in the 2,3-dimethylnaphthalene radical cation. Addu cts 9 and 10 undergo thermal cycloaddition in (H-2)chloroform at 22-de grees-C to give the nitro cycloadduct 16 and hydroxy cycloadduct 15, r espectively. An X-ray crystal structure is reported for hydroxy cycloa dduct 15, as are preliminary results of a single crystal X-ray analysi s of adduct 7.