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 at 0° C. with magnetic stirring and acetic acid (9.2 mL, 0.16 mol) was added. The bath was removed and then the mixture was maintained at room temperature for 1 h with vigorous stirring. The mixture was concentrated in vacuo 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 to the resulting solution was added to 2-(4-bromophenyl)oxirane (400 g, 2 mol) dissolved in THF (300 mL). The reaction mixture was cooled to 0° C. and distilled water (19.8 g, 1.1 mol) was added slowly into the mixture. The resulting mixture was maintained at room temperature for 16 h with magnetic stirring, concentrated and the 1 L 5% EtOAc/Hexane was added to the residue. The resulting mixture was maintained at room temperature for 1 h with vigorous magnetic stirring. The insoluble solid material was filtered away (100% diol by HPLC). The filtrate was concentrated and dissolved in 1 L hexane. The resulting mixture was maintained at room temperature for 1 h with vigorous magnetic stirring. The insoluble solid was filtered off. 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, and Co Salen catalyst).

Provenance & Evidence