Cyclohexanedione to 2-Cyclohexenone Conversion

The reaction of 2,2-disubstituted 1,3-cyclohexanediones 1 with dimethyl methanephosphonate in THF in the presence of LDA gives 3-substituted 2-cyclohexenones 2 in moderate to very good yields. 

Treatment of the steroid derivative 1 with bromine and silver acetate in a mixture of chloroform and pyridine at low temperature followed by quenching of the reaction mixture with aqueous acid gave a mixture of compounds, one of which was shown to be 2. 

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