C([N-]C(C)C)(C)C.[Li+].C(NC(C)C)(C)C.C([Li])CCC.[CH3:21][O:22][C:23]1[CH:31]=[C:30]2[C:26]([CH2:27][CH2:28][C:29]2=[O:32])=[CH:25][CH:24]=1.Cl[CH2:34][C:35](=[O:37])[CH3:36].[Cl-].[Na+]>CCCCCC.O1CCCC1>[CH3:21][O:22][C:23]1[CH:31]=[C:30]2[C:26]([CH2:27][CH:28]([CH2:34][C:35](=[O:37])[CH3:36])[C:29]2=[O:32])=[CH:25][CH:24]=1A lithium diisopropylamide solution, freshly prepared from 3.12 ml of diisopropylamine and 13.8 ml of 1.6N n-butyllithium in hexane, in 40 ml of anhydrous tetrahydrofuran was added dropwise while stirring to a solution, cooled to -70°, of 2.96 g of 6-methoxy-1-indanone in 300 ml of anhydrous tetrahydrofuran. The mixture was stirred at this temperature for an additional 30 minutes and a solution of 1.62 ml of chloroacetone dissolved in 40 ml of anhydrous tetrahydrofuran was subsequently added dropwise over 10 minutes. The reaction mixture was left to come to room temperature over 90 minutes and was stirred at this temperature for an additional 45 minutes. Subsequently, the reaction mixture was poured on to 100 ml of ice, 100 ml of saturated sodium chloride were added and the organic phase was separated. The aqueous phase was extracted once with 300 ml of diethyl ether. The combined organic phases were washed once with 100 ml of saturated sodium chloride solution, dried over magnesium sulfate and concentrated in a vacuum. The red oil obtained was purified by column chromatography on silica gel (hexane/diethyl ether 3:2). There were obtained 2.24 g (56%) of (RS)-6-methoxy-2-(2-oxopropyl)-1-indanone as a yellow solid which was used without further recrystallization in the next reaction.
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