Sodium Hydroxide → 2-(6-Carboxy-2-cis-hexenyl)cyclopent-2-en-1-one

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反応手順

A mixture of 0.194 g. (0.007952 mole) of sodium hydride (free of mineral oil) and 5.5 ml. of dimethylsulfoxide is heated to 70° C. until gas evolution ceases under a nitrogen atmosphere. The resulting solution is cooled below room temperature and treated with a solution of 1.400 g. (0.00316 mole) of 4-carboxybutyltriphenyl phosphonium bromide [E.J. Corey et al., J. Am. Chem. Soc., 91, 5675 (1969)]in 6 ml. of dimethylsulfoxide. To the resulting red solution is added 0.00263 mole of 2-formylmethylcyclopent-2-en-1-one (Example 898) in 2 ml. of dimethylsulfoxide and the mixture is stirred at room temperature for 2.25 hours. The mixture is poured into ice water, sodium hydroxide solution is added to pH 12, and the neutral materials are extracted with diethyl ether. The basic phase is acidified with dilute hydrochloric acid and is extracted with diethyl ether. The organic phase is washed with water and saturated brine, dried (Na2SO4), and evaporated to a semicrystalline mass. The latter is triturated with hot hexane, the solids are filtered off, and the filtrate is evaporated to yield the subject product as an oil.

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