The yellow compound previously obtained by hydrogenolysis of 3-carboxymethylthiojuglone (I; R= H) with Raney nickel is shown to be 5: 8-dihydroxy-1-tetralone (VI; R= H) arising by further reduction of a-hydrojugione (11). Similar treatment of P-hydrojuglone gives the keto- alcohol (IV). IN the preparation of plumbagin (2-methyljuglone) by hydrogenolysis of (I; R= Me) with Raney nickel, a small amount of a yellow by-product (A), mp 164", was isolated (J ...
