C([O:4][C:5]1[CH:12]=[CH:11][C:8]([CH:9]=[O:10])=[C:7]([CH3:13])[CH:6]=1)C=C.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(O)=O>C(OCC)(=O)C.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[CH3:13][C:7]1[CH:6]=[C:5]([OH:4])[CH:12]=[CH:11][C:8]=1[CH:9]=[O:10]The compound of Step B, 13.54 g (76.9 mmole), 1.72 g (7.69 mmole) palladium acetate, and 12.09 g (46.2 mmole) triphenylphosphine were mixed in a 250 ml flask. Formic acid, 3.2 ml (84.6 mmole), was added and the reaction was swirled. Within 15 seconds, the reaction foamed, exothermed and formed a gum which was dissolved in ethyl acetate, washed once with sodium bicarbonate and once with brine. The organic layer was chromatographed on 350 ml silica, eluting with 20%, then 40% ethyl acetate/hexane. The fractions were combined and the product crystallized from methylene chloride/hexane to give 3.61 g (35%) of product which was used without further purification.
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