Dimethylformamide → Methyl 2-(1,4-dioxaspiro[4.5]decan-8-ylidene)acetate

Participants

Reaction Steps

To a DMF (50 mL) solution of trimethyl phosphonoacetate (26 mL), sodium hydride (purity: 55% or higher, 7.03 g) was added in small portions at 0° C. The reaction mixture was warmed to room temperature and stirred for 30 minutes. A DMF (50 mL) solution of 1,4-cyclohexanedione monoethylene ketal (25.2 g) was added, thereto in small portions at room temperature. This suspension was stirred for 19 hours and diluted with a saturated aqueous solution of ammonium chloride, followed by two extractions with ethyl acetate. The organic layer was washed with saturated brine, then dried over sodium sulfate, and then concentrated. The residue was purified by chromatography (hexane/ethyl acetate=5:1) to obtain the title compound (29.7 g, 87%) as a colorless oil.

Provenance & Evidence