Toluene → HCID 57020377, compound

Participants

Reaction Conditions

Reaction Steps

147.5 mg (0.50 mmol) of methyl (2S,3S)-3-t-butoxycarbonylamino-3-phenyl-2-hydroxypropionate and 2.5 cm3 of anhydrous toluene are introduced, under an argon atmosphere, into a 10 cm3 round-bottomed flask equipped with a magnetic stirrer system. 10 grains of 4 Å molecular sieve, 188.5 μl (144.2 mg, 2.0 mmol) of 2-methoxypropene and 12.5 mg (0.05 mmol) of pyridinium p-toluenesulphonate are then added to the suspension obtained. The mixture is allowed to react for 1 hour at a temperature in the region of 20° C. and is then heated to 120° C. and allowed to react at this temperature for 2 hours. The resulting dark-brown reaction mixture is cooled to a temperature in the region of 20° C. 60 cm3 of dichloromethane are added. The organic phase is washed with 5 cm3 of a saturated aqueous sodium hydrogen-carbonate solution, 3 times with 5 cm3 of water and then once with 5 cm3 of a saturated aqueous sodium chloride solution. The organic phase is dried over anhydrous sodium sulphate. After filtration and concentration to dryness under reduced pressure, a residue is obtained which is chromatographed on a column of silica gel, eluting with an ethyl ether/hexane (15/85 by volume) mixture. There are obtained, with a yield of 36%, 60 mg (0.18 mmol) of (4S,5S)-3-t-butoxycarbonyl-2,2-dimethyl-4-phenyl-5-methoxycarbonyl-1,3-oxazolidine, the characteristics of which are the following:

Provenance & Evidence