Improved synthesis of racemic and optically active 4-hydroxycyclohex-2-en-1-one

Article abstract of DOI:10.1016/0957-4166(95)00360-2

A simple and inexpensive synthetic route which affords S-(-)-4-hydroxycyclohex-2-en-1-one (1a) with high stereoselectivity and moderate enantioselectivity is reported. A key step in this procedure involves baker's yeast promoted reduction of 1α,4α,4aα,6,7,8aα-hexahydro-1,4-methanonaphthalene-5,8-dione (3), which affords optically active 8-hydroxy-1α,4α,4aα,8β,8aα-tetrahydro-1,4-methanonaphthalen-5(1H) -one (4a, 80% de, 67% ee) in 32% yield. The absolute configuration of the 3,5-dinitrobenzoate ester of 4a (i.e., 5a) was established unequivocally via single crystal X-ray structural analysis.