Hydrochloric Acid → (2S,4R)-N-methanesulfonyl-2-tert-butyldimethylsilyloxymethyl-4-methanesulfonyloxypyrrolidine

Participants

Reaction Steps

To 160 ml of tetrahydrofuran were added 7.81 g (0.04 mol) of (2S,4R)-N-methanesulfonyl-4-hydroxy-2-hydroxymethylpyrrolidine [IV] 195 mg (1.6 m-mol) of 4-dimethylaminopyridine and 4.86 g (0.048 mol) of triethylamine, and the mixture was stirred. To this mixture was added 6.63 g (0.044 mol) of tert-butylmethylsilyl chloride, and the whole was stirred overnight at room temperature. After concentrating the reaction mixture under reduced pressure, 40 ml of water was added to the residue and the organic phase was taken up with 120 ml of ethyl acetate three times. The extract was washed with 40 ml of a saturated solution of sodium chloride and dried over magnesium sulfate and concentrated until dryness under reduced pressure. The residue was dissolved in 100 ml of pyridine and 5.05 g (0.044 mol) of methanesulfonyl chloride was slowly added dropwise to the mixture under agitation and icecooling. The mixture was allowed to stand overnight and then incorporated under ice-cooling with 400 ml of 10% hydrochloric acid. The mixture was extracted with 150 ml of ethyl acetate three times and the extract was washed with 75 ml of a saturated aqueous solution of sodium hydrogen carbonate and then with 75 ml of a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. The extract was concentrated until dryness under reduced pressure to obtain 12.56 g (yield: 81%) of an oily substance which, after recrystallization from a mixture of isopropyl ether and n-hexane, gave crystals having a melting point of 51.5°-52.5° C. [α]D20 =-28.57° (c=1, EtOH)

Provenance & Evidence