(3R,4S)-3,4-difluoropyrrolidine;hydrochloride

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (4R)-1-(tert-butoxycarbonyl)-4-hydroxy-L-proline (2.31 g, 10 mmol), was coupled with (3R,4S) -rel-3,4-difluoropyrrolidine hydrochloride (1.44 g, 10 mmol, Preparation 4), in a manner analogous to that described in Preparation 1, Step 1, to afford 2.15 g (67%) of the title product as an off-white foam. MS m/z 321 (MH+). that described in Preparation 1, Step 1

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (4R)-1-(tert-butoxycarbonyl)-4-hydroxy-L-proline (2.31 g, 10 mmol), was coupled with (3R,4S)-rel-3,4-difluoropyrrolidine hydrochloride (1.44 g, 10 mmol, Preparation 4), in a manner analogous to that described in Preparation 1, Step 1, to afford 2.15 g (67%) of the title product as an off-white foam. MS m/z 321 (MH+). that described in Preparation 1, Step 1