反应详情

1,1-Dimethoxy-2-nitrosocyclohexane dimer was prepared as described in Example 1 from 1-methoxycyclohexene (46.8 g., 0.417 mole), methyl nitrite (30.6 g., 0.501 mole) and boron trifluoride-etherate (0.25 ml., 0.28 g., 2.0×10-3 mole) in 250 ml. of sulfur dioxide. The crude nitroso dimer, 76.0 g. of a gummy yellow-green solid still containing traces of sulfur dioxide, was obtained by the method described earlier. Without purification, the dimer was subjected to isomerizing conditions in methanol/sodium methoxide solution. Filtration through celite (to remove colloidal solids that had formed) and evaporation afforded 66.0 g. of an off-white slightly moist solid. Recrystallization from 180 ml. of ether at -70° C. gave 26.8 g. (37.2%) of 1,1-dimethoxy-2-oximinocyclohexane as colorless fine needles, m.p. 112°-116° C. An additional 2.9 g. (4.0%) of slightly impure oxime was obtained from the mother liquor as a white powder, m.p. 105°-112° C.