Hexane → Dimethyl 4,4-dimethyl-2-oxoheptylphosphonate

Participants

Reaction Conditions

Reaction Steps

Dimethyl methylphosphonate (11.7 g, 102 mmol) was dissolved in anhydrous THF (200 ml) and the resulting solution was cooled to -78° C. under argon atmosphere. A solution of n-butyl lithium in hexane (1.63N, 62.3 ml, 102 mmol) was added and the mixture was stirred for 30 minutes. A solution of ethyl 3,3-dimethylhexanoate (7.00 g, 40.6 mmol) in anhydrous THF (50 ml) was added to the reaction mixture at -78° C. andthe mixture was stirred for 30 minutes and then at room temperature for further 2 hours. Acetic acid was added to neutralize the solution. Water (20 ml) was added and then the solution was concentrated. The resulting residue were partitioned between ethyl acetate (200 ml) and water (10 ml). The ethyl acetate layer was separated, washed with water (80 ml) and with brine (100 ml), dried over anhydrous magnesium sulfate, and concentrated. The residue was distilled under reduced pressure to give oily product, dimethyl 4,4-dimethyl-2-oxoheptylphosphonate (8.11 g, 32.4 mmol, 79.8%, b.p.: 101°-104° C./0.03 mmHg). The structure was identified by the following data.

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