Methanol → (2s,4r)-4-(n-Tert-butoxycarbonylglycylamino)-2-hydroxymethyl-n-tert-butoxycarbonylpyrrolidine

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Reaction Steps

Methanol (8 mL) was added over a period of 1 hr to a refluxed mixture of trans-4-N-tert-butoxycarbonylglycylamino)-N-tert-butoxycarbonyl-L-proline methyl ester (Compound D103 (B), 1.39 g) and lithium borohydride (328 mg) in tetrahydrofuran (30 mL). After being cooled, water was added to the mixture and the product was extracted twice with chloroform. The combined organic layers were dried over anhydrous sodium sulfate, then evaporated in vacuo and the residue was purified by silica gel column chromatography (chloroform:methanol=95:5, v/v) to give title compound (1.31 g): 1H NMR (400 MHz, CDCl3) δ 1.46 (s, 9H), 1.47 (s, 9H), 1.89 (m, 1H), 1.98 (m, 1H), 3.34 (dd, J=11.7, 3.9 Hz, 1H), 3.60 (d, J=5.9 Hz, 1H), 3.64 (d, J=5.9 Hz, 1H), 3.69 (m, 1H), 3.75 (d, J=5.9 Hz, 1H), 4.04 (m, 1H), 4.42 (m, 1H), 4.55 (m, 1H), 5.15 (m, 1H), and 6.44 (m, 1H).

Provenance & Evidence