The standard procedure was followed using N-(4-cyano-2-t-butyldimethylsilanoxyphenyl)-N′-(2-bromophenyl)carbodiimide (102 mg, 0.24 mmol), diisopropylethylamine (60 μL, 0.26 mmol), hydroxy L-proline methyl ester hydro chloride (44 mg, 0.26 mmol) and TBAF (0.29 mL, 0.29 mmol) in THF (2.5 mL) and methanol (0.1 mL) to give 80 mg (78%) of 4-[[(6R,7aS)-2-(2-bromophenyl)-hexahydro-6-hydroxy-1-oxo-3H-pyrrolo[1,2-c]imidazol-3-ylidene]amino]-3-hydroxybenzonitrile as a tan powder. MS(EI) m/e 427 (100 (M+)).
