Acetic Acid → HCID 86640928, compound

Participants

Reaction Steps

To a −78° C. solution of (3S, 4aS, 8aR) 6-oxo-2-tert-butoxycarbonyl-1,2,3,4,4a, 5,6,7,8,8a-decahydroisoquinoline-3-carboxylic acid (6.88 g, 21.14 mmol)(see Preparation 2, Steps A and B, below and Scheme III, Step A generally) and cerium trichloride heptahydrate (7.9 g, 21.2 mmol) in absolute ethyl alcohol (90 mL), under nitrogen sodium borohydride (1.24 g, 32.73 mmol) was added in portions. The resulting mixture was slowly warmed up to room temperature over 5 hours. The reaction mixture was cooled down to 0° C. and acetic acid (50% in water, 25 mL) was carefully added. The resulting mixture was stirred for 1 hour at room temperature and the solvent was removed in vacuo. To the resulting material water and ethyl acetate were added and the phases separated. Aqueous layer was extracted with ethyl acetate (3×). The combined organic phases were dried, filtered and concentrated in vacuo. Flash chromatography (silicagel, 70% ethyl acetate/hexane) gave ethyl (3S, 4aS, 6S, 8aR) 6-hydroxy-2-tert -butoxycarbonyl-1,2,3,4,4a, 5,6,7,8,8a-decahydroisoquinoline-3-carboxylate (2.4 g, 35%) and the title compound (4.15 g, 60%)

Provenance & Evidence