Methanol → (2S,4R)-1-((2S,3R)-2-(tert-butoxycarbonylamino)-3-ethyl-5-methylnon-8-enoyl)-4-hydroxypyrrolidine-2-carboxylic acid

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Reaction Steps

To a solution of (2S,4R)-methyl 1-((2S,3R)-2-(tert-butoxycarbonylamino)-3-ethyl-5-methylnon-8-enoyl)-4-hydroxypyrrolidine-2-carboxylate (1.5 g, 3.40 mmole) in THF/water (16 mL, 1:1) was added LiOH (286 mg, 6.80 mmole) followed by 3 mL of methanol at room temperature. The reaction mass was stirred at room temperature for overnight. The solvent was evaporated under reduced pressure and the residue was diluted with water and acidified with aqueous 1.5 N HCl solutions. The aqueous solution was extracted with ethyl acetate (20 mL×3). The combined organic layer was dried over anhydrous Na2SO4 and concentrated under reduced pressure to get desired product (1.3 g, 90%) as white solid. 1H NMR (400 MHz, DMSO-d6): δ ppm 0.81-0.93 (m, 6H), 1.12-1.29 (m, 5H), 1.30-1.50 (m, 11H), 1.71-1.80 (m, 2H), 1.91-2.51 (m, 4H), 3.57-3.59 (m, 1H), 4.27-4.35 (m, 3H), 4.92-4.97 (m, 2H), 5.01-5.15 (m, 1H), 5.74-5.79 (m, 1H), 6.30-6.80 (m, 1H), 12.50 (sb, 1H). MS: MS m/z 427.6 (M++1).

Provenance & Evidence