Hydrochloric Acid → trans-5-(2-Amino-1,2,3,4-tetrahydro-6,7-dimethoxy-1-naphthyl)-2-propyl-4-oxazolemethanol

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Reaction Steps

To a solution of the compound from step 29d (1.16 g, 2.52 mmol) in 40 mL of ethanol was added 10 mL of 6 N HCl. The mixture was stirred for 30 min at room temperature, and zinc dust was added in portions until the yellow solution turned colorless. Satd. NaHCO3 solution was added until the mixture was at pH 8-9. The solid was removed by filtration and washed with methylene chloride. The flitrate and washings were combined, dried over MgSO4, concentrated, and purified by chromatography on silica gel, eluting with 5-40% methanol (containing 5%NH4OH) in methylene chloride, to afford 742 mg (85% yield) of the title product as a 1:6.5 mixture of cis:trans isomers. Recrystallization from 1:1 hexane:ethyl acetate provided the pure trans isomer as a solid. MS: 347(M+H)+. NMR (CDCl3) δ:6.62 (s, 1H), 6.29 (s, 1H), 4.62 and 4.52 (abq, J=13 Hz, 2H), 4.02 (d, J=10 Hz, 1H), 3.87 (s, 3H), 3.68 (s, 3H), 3.17 (m, 1H), 3.03-2.79 (m, 2H), 2.65 (t, J=8 Hz, 2H), 2.18 (m, 1H), 1.81 (m, 1H), 1.72 (sx, J=8 Hz, 2H), 0.92 (t, J=8 Hz, 3H).

Provenance & Evidence