Iodine → (3S,4S)-(+)-1-Benzyl-3,4-pyrrolidindiol

Participants

Reaction Steps

A solution of 50.7 g (0.2 mole) iodine in 200 ml THF was added dropwise to a suspension of 22.1 g (0.1 mole) (3R,4R)-1-benzyl-3,4-dihydroxy-2,5-pyrrolidinedione (IIb) and 15.2 g (0.4 mole) sodium boron hydride in 500 ml THF within 1 h at 12°-15° C. The mixture was then heated 2 d under argon on a reflux. After cooling off, 50 ml methanol were added and after the end of the development of gas the mixture was evaporated to dryness. The residue was taken up in 60 ml water and compounded with 15 ml conc. hydrochloric acid until an acidic reaction. After 30 min agitation, 150 ml 20% potash lye were added and [the mixture] extracted twice with 250 ml MTBE each time. After evaporation, 19.2 g colorless, crystalline residue remained. Recrystallization from 60 ml ethyl acetate yielded in 2 fractions 10.4 g (53.9%) (3S,4S)-1-benzyl-3,4-dihydroxypyrrolidine (IIIb).

Provenance & Evidence