Chloranil → Estra-4,6-diene-3,17-dione
Reaction equation
[CH3:1][C@:2]12[CH2:18][CH2:17][C@H:16]3[C@@H:7]([CH2:8][CH2:9][C:10]4[C@@H:15]3[CH2:14][CH2:13][C:12](=[O:19])[CH:11]=4)[C@@H:6]1[CH2:5][CH2:4][C:3]2=[O:20].C1(Cl)C(=O)C(Cl)=C(Cl)C(=O)C=1Cl.CCOC(C)=O.CCCCCC>C(O)C>[CH3:1][C@:2]12[CH2:18][CH2:17][C@H:16]3[C@@H:7]([CH:8]=[CH:9][C:10]4[C@@H:15]3[CH2:14][CH2:13][C:12](=[O:19])[CH:11]=4)[C@@H:6]1[CH2:5][CH2:4][C:3]2=[O:20]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of dione 53 (5.0 g, 18.36 mmol) and chloranil (5.4 g, 22 mmol) in dry ethanol (500 mL) was stirred at 60-65° C. for 2 h. The reaction mixture was concentrated under reduced pressure, and the residue was triturated with dichloromethane. The solid was removed by filtration, and the filtrate was concentrated to give a brown gum. Chromatography (20% EtOAc/hexane) yielded crude dione 54 as a yellow solid (2.3 g, 46%): 1H NMR (300 MHz, CDCl3) δ0.94 (s, 3, CH3), 5.78 (s, 1), 6.25 (m, 2).