C=[CH:2][C@@H:3]1[C@:20]2([CH3:21])[C@H:6]([C@H:7]3[C@H:17]([CH2:18][CH2:19]2)[C@:15]2([CH3:16])[C:10](=[CH:11][C:12](=[O:22])[CH2:13][CH2:14]2)[C:9](=O)[CH2:8]3)[CH2:5][CH2:4]1.ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl.[Na].O>O1CCOCC1.C(OC)(C)(C)C>[CH2:2]=[C:3]1[CH2:4][CH2:5][C@H:6]2[C@H:7]3[C@H:17]([CH2:18][CH2:19][C@:20]12[CH3:21])[C@:15]1([CH3:16])[C:10](=[CH:11][C:12](=[O:22])[CH:13]=[CH:14]1)[CH2:9][CH2:8]3Refer to FIG. 190. A solution of 17-methylenandrost-4-en-3-one (9, 1.0001 g, 3.5160 mmol) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 2.43 g, 10.7 mmol) in dioxane (60 ml, freshly distilled after overnight reflux over sodium) was refluxed 6 h and then cooled with swirling in tap water. Methyl t-butyl ether (MTBE, 50 ml) was added and the suspension was filtered through diatomaceous earth. The residue was washed with two 50 ml portions of MTBE and the combined filtrates were concentrated under reduced pressure. Flash chromatography of the residue (20% ethyl acetate/hexanes on silica gel) followed by recrystallization from 95% ethanol gave off-white crystals (498.9 mg, 1.767 mmol, 50%), m.p. 155-157° C.
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