Acetic Acid → (R)-(+)-1,2-Epoxydodecane

Participants

Reaction Steps

An oven-dried round bottom flask containing a magnetic stir bar was charged with the (R,R)-HKR catalyst (Schaus, et al., J. Am. Chem. Soc. 2002, 124, 1307-1315); CAS Number 176763-62-5, 1.31 g, 2.17 mmol. Dichloromethane (34 mL) and then glacial acetic acid (1.30 mL) were added to the flask. The resulting solution was stirred vigorously for 1.5 h; during this time the color of the mixture changed from dark red to brown. The solvent was removed by rotary evaporation until the material appeared dry. 1,2-epoxydodecane (40.0 g, 217 mmol) then isopropyl alcohol (reagent grade, 47 mL) were added to the flask containing the oxidized catalyst and a magnetic stir bar. The flask was immersed in an ice bath. H2O (2.15 mL, 119 mmol, 0.55 equiv relative to epoxide) was added dropwise to the stirred mixture. The flask was sealed with a rubber septum and the solution was allowed to warm to room temperature. After stirring for 2 days, the reaction mixture was diluted with ˜200 mL of hexanes. The resulting solution was filtered through paper to remove the white precipitate (1,2-diol). The filtrate was concentrated by rotary evaporation. The resulting dark red oily liquid was dissolved in ˜150 mL of hexanes and filtered in order to remove a substantial amount of white crystalline precipitate (diol). The filtrate was transferred into a 250 mL round bottom flask and concentrated by rotary evaporation. The desired product was isolated by distillation under vacuum (literature: 124° C./15 mm Hg). The desired product (14.3 grams, 71.5% of theoretical yield) was collected as a clear oil. The product was determined to be 100% ee by chiral chromatography of the 2-naphthylenethiol derivative.

Provenance & Evidence