3-Allyl-4-allyloxy-5-methoxybenzoic acid → 9-Methoxy-2,5-dihydrobenzo[b]oxepine-7-carboxylic acid

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of 3-allyl-4-allyloxy-5-methoxybenzoic acid (200 mg, 0.81 mmol) in CH2Cl2 (20 mL) at room temperature was added benzylidene-bis-(tricyclohexylphosphine)dichlororuthenium (Grubb's catalyst, 35 mg, 0.04 mmol, 0.05 eq.). After stirring for 2 h the reaction was diluted with EtOAc (150 mL) then extracted with 2.0 N NaOH (100 mL). Aqueous layer was treated with brine (100 mL) then acidified to pH 5 using 1.0 N HCl. The aqueous layer was then extracted with EtOAc (2×200 mL). The organic layer was dried over MgSO4 and then concentrated in vacuo to afford 9-methoxy-2,5-dihydrobenzo[b]oxepine-7-carboxylic acid (179 mg, 100%) which was used without further purification.

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