Methoxymethyl-triphenylphosphonium chloride → HCID 70002150, compound

Participants

Reaction Conditions

Reaction Steps

14.27 g (1.6 eq.) of (methoxymethyl)triphenylphosphonium chloride was suspended in 50 ml of abs. THF and deprotonated at a temperature of −10° C. and −5° C. by adding via syringe 25.2 ml of 1.6 M n-butyllithium (1.55 eq., in hexane). The resultant red ylide solution was cooled to −75° C. and treated with 6.20 g (26.0 mmol) of 8-bromo-3,4-dihydro-2H-benzo[b]oxepin-5-one dissolved in 13 ml of abs. THF. The mixture was then kept for 0.2 h at −78° C. and for 1 h at room temperature, poured onto crushed ice and extracted with diethylether. The organic phase was washed with water and dried over magnesium sulfate, filtrated and the solvent evaporated to yield a crude product which was purified by flash chromatography (SiO2, hexane/ethylacetate=95/5). Thereby, 5.85 g of 8-bromo-5-methoxymethylene-2,3,4,5-tetrahydrobenzo[b]oxepine was obtained as E/Z-mixture which was hydrolyzed as follows:

Provenance & Evidence