[CH2:1]([O:3][C:4]([CH2:6][CH2:7][CH:8]1[CH2:17][CH2:16][C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:9]1=O)=[O:5])[CH3:2].[C:19](P(=O)(OCC)OCC)#[N:20].[C-]#N.[Li+].O>C1COCC1.CN(C=O)C>[C:19]([C:9]1[C:10]2[C:15](=[CH:14][CH:13]=[CH:12][CH:11]=2)[CH2:16][CH2:17][C:8]=1[CH2:7][CH2:6][C:4]([O:3][CH2:1][CH3:2])=[O:5])#[N:20]2-(2-Ethoxycarbonylethyl)-3,4-dihydro-1(2H)-naphthalenone (19.7 g, 80 mmol), from Step 1, was dissolved in 200 mL of dry THF and diethyl cyanophosphonate (23.6 mL, 160 mmol), commercially available from Aldrich Chemical Company, was added, followed by 160 mL of a 0.5M solution of lithium cyanide in DMF. The reaction mixture was stirred at ambient temperature overnight and then poured into water. The aqueous mixture was extracted with three portions of diethyl ether. The ether extracts were dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was dissolved in 400 mL of toluene and 20 g of p-toluenesulfonic acid was added. The reaction mixture was heated at reflux for 3 h and allowed to cool to ambient temperature. The toluene solution was washed with 5% aqueous sodium bicarbonate, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by chromatography on silica gel eluted with 10% ethyl acetate in hexane to give 13.1 g (64.2% yield) of the title compound; MS DCl--NH3 M/Z: 273 (M+NH4)+.
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