[Na].C(OCC)(=O)[CH2:3][C:4](OCC)=[O:5].[CH3:13][C:14]1([CH3:31])[CH2:18][C:17]2[C:19]([CH3:30])=[C:20]([CH3:29])[C:21]([CH:24]=[CH:25][C:26](=[O:28])[CH3:27])=[C:22]([CH3:23])[C:16]=2[O:15]1.[OH-].[Na+]>CO>[CH3:13][C:14]1([CH3:31])[CH2:18][C:17]2[C:19]([CH3:30])=[C:20]([CH3:29])[C:21]([CH:24]3[CH2:3][C:4](=[O:5])[CH:27]=[C:26]([OH:28])[CH2:25]3)=[C:22]([CH3:23])[C:16]=2[O:15]1To a solution of 3.8 g of sodium 140 ml of absolute methanol was added 25 ml of diethyl malonate. After stirring for 20 minutes, the mixture was added 42.4 g of the 4-(2,3-dihydro-2,2,4,5,7-pentamethylbenzofuran-6-yl)-3-butene-2-one in 140 ml of absolute methanol, refluxed for 4 hours and 200 ml of 10% aqueous solution of sodium hydroxide. The reaction mixture was cooled to room temperature and washed with diethyl ether. 2N aqueous solution of hydrochloric acid was added dropwise into the aqueous layer until the bubble ceased. And then, solid was dissolved in ethyl acetate and washed with water. The combined organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to afford 38.8 g of 5-(2,3-dihydro-2,2,4,5,7-pentamethylbenzofuran-6-yl)-3-hydroxycyclohex-2-en-1-one.
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