3-(2-Benzyloxyethyl)-2-oxo-3,9-diaza-bicyclo[3.3.1]nonane-9-carboxylic acid benzyl ester (Compound 5, 0.15 g, 0.36 mmol) was dissolved in MeOH (5 mL), and palladium (10%) on activated carbon (0.03 g) was added. Hydrogen was applied via balloon for 1 hour. The black suspension was then filtered through compacted Celite, and the methanol was removed by high-vacuum rotary evaporator to give Compound 6 (0.09 g, 90%) as a thick oil, which was of sufficiently good quality to be advanced to the coupling reaction without further purification.
