Ammonium Chloride → 1,5-Dimethyl-8-oxabicyclo[3.2.1]oct-6-en-3-one

Participants

Reaction Steps

To a stirred slurry of 2,4-dibromo-1,5-dimethyl-8-oxabicyclo[3.2.1]oct-6-en-3-one (18.0 g) in a saturated methanolic solution of ammonium chloride (514 ml) was added portionwise zinc/copper couple (51 g) over 30 minutes at 23° C. The suspension was stirred for an additional 2 hours and filtered. The filtrate was diluted with a saturated Na2H2 -ethylenediaminetetraacetic acid solution (400 ml). Extraction with methylene chloride (5×100 ml) and drying (MgSO4) produced, upon evaporative removal of solvent, the desired ketone (9.0 g). Bulb-to-bulb distillation <80° C. and 0.5 mm afforded the desired product (7.3 g) as colorless crystals, m.p. 62°-63° C.

Provenance & Evidence