KO2 oxidation of cis-4, 5-dihydro-4, 5-dihydroxy-3-nitropyrene, 1 gives the known lactone, 3- nitro-5H-phenanthro [4, 5-bcd] pyran-5-one, 2. Similarly the analogous 4, 5-dihydrodiol, 3, gives the known lactone, 1-nitro-5H-phenanthro [4, 5-bcd] pyran-5-one, 4. While the yield of 2 is 80%, it is only 16% for 4. A study of the latter oxidation, relying especially on the use of HPLC, led to a change in the conditions that increased the yield of 4 from 16 to 88%. The ...
