Benzene → 8-Methylidene-1,4-dioxaspiro[4.5]decane

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Reaction Steps

1,4-Dioxaspiro[4.5]decan-8-one (21 g, 0.13 mol) in dry benzene (50 mL, 0.6 mol) was added to ethylenetriphenylphosphorane [prepared from dimsyl sodium and methyltriphenylphosphonium bromide (106 g, 0.291 mol) in dimethyl sulfoxide (600 mL, 8 mol)] The mixture was stirred at room temperature overnight and poured into a separating funnel containing ethyl ether (500 mL) and water (500 mL). The organic layer was separated and the aqueous phase was extracted with ethyl ether (2×500 mL). The combined ether layers were washed with water (500 mL) and brine (500 mL), and dried. The solvents were removed under reduced pressure and the residue was purified by flash chromatography to afford the desired product (18.0 g, 85%).

Provenance & Evidence