1,8-Diazabicyclo(5.4.0)undec-7-ene → (2S,4R)-1-benzyloxycarbonyl-2-[{3-(ethoxycarbonyl)-2-propenyl}oxymethyl]-4-methanesulfonyloxypyrrolidine

Participants

Reaction Steps

To a solution of (2S,4R)-1-benzyloxycarbonyl-2-[{3-(ethoxycarbonyl)-2-methanesulfonyloxypropyl}oxymethyl]-4-methanesulfonyloxypyrrolidine (3.7 g) in tetrahydrofuran (40 ml) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (5.1 ml) at ambient temperature and the mixture was stirred for one hour. Removal of the solvent in vacuo gave an oil which was dissolved in a mixture of ethyl acetate (100 ml), water (50 ml) and 1N-hydrochloric acid (10 ml). The organic layer was separated, washed twice with brine (50 ml) and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was chromatographed on silica gel (200 ml) eluting with a mixture of hexane and ethyl acetate (1:1 V/V) to give (2S,4R)-1-benzyloxycarbonyl-2-[{3-[ethoxycarbonyl)-2-propenyl}oxymethyl]-4-methanesulfonyloxypyrrolidine (2.72 g).

Provenance & Evidence