2-Methoxy-1,3-butadiene → 3,4,4a, 12a-Tetrahydro-11-chloro-6,7-dihydroxy-2,5,12(1H)-naphthacenetrione

Participants

Reaction Steps

10-Chloro-8,9-dihydroxy-1,4-anthracenedione (compound 3) (100 mg), 2-methoxy-1,3-butadiene (564 mg) and dry benzene (10 ml) were heated in a sealed tube for 4 h at 130°. After cooling the crude solution was preparatively chromatographed on silica gel layers containing oxalic acid (2%) with chloroform as eluant. The major yellow band was recovered to give the product (compound 9) as a yellow crystalline solid (85 mg, 68%).

Provenance & Evidence