Ketonitrophenols from mestranol and related compounds

Mestranol (17a-ethynylestradiol 3-methyl ether), when placed on a carrier such as powdered silica gel and exposed to the atmosphere, is converted to a yellow product. The compound formed was shown to be 1a-ethynyltetrahydro-1β-hydroxy-4 - (2 - hydroxy - 5 - methoxy - 3 - nitrophenethyl) - 7a - methyl-5(4H)-indanone. The 3-methyl ethers of three other steroids having aromatic A rings yielded products of a similar type. Identical compounds were prepared from the respective steroids by treatment with nitrating agents in acetic acid. This reaction in acetic acid is light catalyzed. An independent synthesis of a model compound, 6-(2-hydroxy-5-methoxy-3-nitrophenyl)-3-hexanone, established the position of the constituents on the aromatic ring as well as the location of the carbonyl. The mechanism proposed for the formation of these products is an initial oxidation of the 1-substituted tetralin to form a hydroperoxide, which is ionically decomposed to form a ketophenol. The phenol is then nitrated in the ortho-position.