40562-09-2

1779-49-3

826-73-3

40562-09-2

GENERAL METHOD: To a stirred suspension of methyltriphenylphosphonium bromide (1.5 eq.) in diethyl ether (25-45 mL) under argon protection is slowly added dropwise a tetrahydrofuran (1.5 eq.) solution of 1 M potassium tert-butanolate. The reaction mixture immediately turns yellow. After refluxing the reaction for 1 hour, 1-benzocycloheptanone (1.0 eq.) was added in batches. The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the reaction was quenched with deionized water (5-8 mL). The organic phase was separated and the aqueous phase was extracted with ether (2 x 10 mL). The organic phases were combined, washed sequentially with deionized water (20 mL x 2) and saturated saline (20 mL x 1), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give the crude product. The crude product was purified by an appropriate method (e.g., column chromatography) to obtain the target product 5-methylene-6,7,8,9-tetrahydro-5H-benzo[7]rotaxene.