Acetic Acid → (R)-4-Bromostyrene oxide

Participants

Reaction Steps

(R,R)-(−)-N,N′-Bis(3,5-di-tert-butyl-salicylidene-1,2-cyclohexane-diaminocobalt(II) (9.7 g, 0.016 mol) was dissolved in 100 mL of toluene in an open flask with magnetic stirring, and acetic acid (9.2 mL, 0.16 mol) was added. The mixture was maintained at room temperature for 1 h with vigorous magnetic stirring. The mixture was concentrated to a brown solid, and then the residue was put under high vacuum overnight. The brown residue was dissolved in 100 mL of THF, and the resulting solution was added to 2-(4-bromophenyl)oxirane (400 g, 2 mol) in 300 mL THF solution. The reaction mixture was cooled to 0° C. Distilled water (19.8 g, 1.1 mol) was added slowly into the mixture. The resulting mixture was maintained at room temperature overnight with magnetic stirring. The reaction mixture was concentrated and 1 L 5% EtOAc/Hexane was added to the residue. The insoluble solid was filtered off (100% diol by HPLC). The filtrate was concentrated, and put under high vacuum for 2 h to yield a brown oil (250 g, a mixture of desired product, trace amount of diol byproduct, and Co Salen catalyst) which was carried on to the next step without further purification.

Provenance & Evidence