N-bromobutanimide → HCID 53964107, compound

Participants

Reaction Steps

To a refluxing solution of the acetate 4 (19 mg) in CCl4 (2 ml), N-bromosuccinimide (9 mg) was added and the mixture was refluxed for 20 min under argon. After cooling, the resulting precipitate was filtered off, and the filtrate was evaporated under vacuo. The residue was dissolved in xylene (1.5 ml) and dropped into a refluxing solution of s-collidine (0.5 ml) in xylene (1.5 ml). After refluxing for 10 min, the mixture was extracted with ethyl acetate. The crude product was dissolved in acetone (5 ml) and treated with p-toluenesulfonic acid (10 mg) by stirring for 14 hr at room temperature. After addition of water, the mixture was extracted with ethyl acetate. The reaction product was purified with preparative TLC (benzene-ethyl acetate, 50:1; two times) to give the 5,7-diene 5 (4.9 mg); UV, λMax (EtOH)262(sh), 271, 282, 293 nm.

Provenance & Evidence