1.1: 2,2'-isopropylidene bis[(4S)-4-tert-butyl-2-oxazoline]; Cu(OTf)2 / CH2Cl2 / 0.5 h / 20 °C 1.2: 86.6 percent / CH2Cl2 / 22 h / 20 °C 2.1: 92 percent / aq. NaIO4 / methanol / 20 °C View Scheme

1.1: 2,2'-isopropylidene bis[(4S)-4-tert-butyl-2-oxazoline]; Cu(OTf)2 / CH2Cl2 / 0.5 h / 20 °C 1.2: 86.6 percent / CH2Cl2 / 22 h / 20 °C 2.1: 92 percent / aq. NaIO4 / methanol / 20 °C View Scheme

1.1: 2,2'-isopropylidene bis[(4S)-4-tert-butyl-2-oxazoline]; Cu(OTf)2 / CH2Cl2 / 0.5 h / 20 °C 1.2: 86.6 percent / CH2Cl2 / 22 h / 20 °C 2.1: 92 percent / aq. NaIO4 / methanol / 20 °C View Scheme

1.1: anhydrous zinc trifluoromethanesulfonate; chiral 4-tert-butyl-4,5-dihydro-1,3-oxazole-based reagent / toluene / 10 - 20 °C 1.2: toluene / 26 h / 10 °C 1.3: magnesium monoperoxyphthalate hexahydrate / methanol / 0 °C 2.1: periodic acid / diethyl ether / 0 °C View Scheme