N.[Na].[NH2-].[Na+].[CH3:5][C:6]([CH3:11])=[CH:7][C:8](=[O:10])[CH3:9].Br[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17]>CCOCC>[CH2:13]([CH:7]([C:6]([CH3:11])=[CH2:5])[C:8](=[O:10])[CH3:9])[CH2:14][CH2:15][CH2:16][CH3:17]100 ml of liquid ammonia was condensed into a 2-neck flask fitted with a dropping funnel, inlet tube, and dry-ice condenser. A few crystals of ferric chloride were added, followed by the addition of 2.3 g (0.1 mole) of sodium. When the sodium was converted to sodium amide, the deep blue color changed to gray. A solution of 10 g (0.1 mole) of 4-methyl-3-pentene-2-one in 10 ml of ether was added dropwise, resulting in a green-blue solution. After 15 minutes a solution of 1.5 g (1 equivalent) of bromopentane in 5 ml of ether was added, changing the color to light brown. After 1 hour of stirring, the ammonia was allowed to evaporate and ether and water were added. The organic layer was separated, washed with water, washed with two 10 ml portions of 5% HCl, and dried over MgSO4. Evaporation of the ether yielded 15 g (88% yield) of 3-pentyl-4-methyl-4-pentene-2-one: ##STR15##
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