3-Quinuclidinone → 3-Quinuclidinol hydrochloride

Participants

Reaction Steps

To a solution of 0.09 g (56.25 mmol) 3-quinuclidinone and 4.15 g (18.75 mmol) Phe-O-t-Bu in 50 ml methanol was added over a 12 hour period a solution of 2.95 g (46.9 mmol) sodium cyanoborohydride in 13 ml methanol. After stirring for an additional 8 hours, 5.78 g (50.0 mmol) pyridine hydrochloride was added and after 11/2 hours stirring, sodium chloride was removed by filtration. The filtrate was concentrated to a foam which was treated with 15 ml methanol and 50 ml ethyl acetate to give a slurry of the byproduct 3-hydroxy quinuclidine hydrochloride (74% of excess) which was removed by filtration. The filtrate was concentrate to an oil and charged with 10 ml methanol to a 5×200 cm column of LH-20 and eluted with methanol. The product fraction contained 6.54 g of a mixture of diastereomers in a 55:45 ratio as established by HPLC.

Provenance & Evidence