Preparation and photochemical rearrangements of 2-phenyl-2,5-cyclohexadien-1-ones. An efficient route to highly substituted phenols

The synthesis of 2 phenyl-2,5-cyclohexadien-1 ones la-e and 2a-b from methy l 3-phenylbenzoate 4 and methyl 2-methoxy-5-phenylbenzoate 8 by the Birch r eduction alkylation methodology is described. 1a-c and 2a-b undergo regiosp ecific photorearrangements at 300 nm to give tetrasubstituted phenols 14a-c and pentasubstituted phenols 18a-b, respectively. The type A photoproducts 17a-b resulting from irradiation of 2a-b at 366 nm have been isolated as s imilar to1:1 diastereomer mixtures. When an optimized condition is applied, a single diastereomer of 17a is obtained.