Synthesis of cis- and trans-5,8-dihydroxy-5,6,7,8-tetrahydro-1,4-naphthoquinone.

Cis- and trans-5,8-dihydroxy-5,6,7,8-tetrahydro-1,4-naphthoquinone (1a, 1b) were for the first time synthesized from 5,8-dihydroxy-1,4-naphthoquinone (naphthazazine) (6) as a starting material and racemic triol (3) was first synthesized from 7. The configuration of 1a was determined by X-ray analysis.