Synthesis of Juglone and its Derivatives

Juglone (1), plumbagin (2) and isoplumbagin (3) were synthesized from the natural product 4,8-dihydroxy naphthol- β -D-glucoside (4) which existed large amount in barks of Juglans mandshurica . Juglone was achieved directly by deglycosylation catalyzing with CAS in 78 % yield. Plumbagin was synthesized by five steps with an overall yield of 22 %. Isoplumbagin was synthesized by six steps in 24 % yield.