Tributylstannane → HCID 86748804, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of N-allyloxycarbonyl-4-amino-5-benzyloxy-2-oxotetrahydrofuran (407.6 mg, 1.399 mmol) and tert-butoxycarbonyl-valinyl-alanine (807 mg, 2.8 mmol) in 10 mL of dichloromethane was added ~20 mg of (PPh3)2PdCl2 followed by tri-n-butyltin hydride (415 μL, 1.54 mmol) dropwise over two minutes. An additional 100 μl of tri-n-butyltin hydride was added dropwise until the color of the reaction mixture had turned dark orange. Dimethylformamide (5 mL0 was added followed by hydroxybenzotriazole (567 mg, 4.2 mmol). The mixture was cooled to 0° C. and ethyl dimethylaminopropyl carbodiimide (295 mg, 1.54 mmol) was added. After 16 hours at ambient temperature, the mixture was diluted with ethyl acetate and washed three times with dilute hydrochloric acid, and three times with dilute sodium bicarbonate. The mixture was dried over sodium sulfate, filtered, and concentrated. The residue was purified by MPLC on silica-gel (22×300 mm column, 50% ethyl acetate in hexane as eluent) to afford 590.4 mg (91%) of the title compound as a mixture of two diastereomers: 1H NMR (400 MHz, CD3OD) δ7.4-7.05 (m, 5H, Ar--H), 5.63 (d, 0.5H, CHOBn), 5.45 (d, 0.5H, CHOBn), 4.9-4.6 (m, 3H, CH2Ph, CHN), 4.4-4.2 (m, 2H, CHN), 3.83 (m, 1H, CHN), 3.03 (dd, 0.5H, CHHCO2), 2.77 (dd, 0.5H, CHHCO2), 2.61 (dd, 0.5H, CHHCO2), 2.47 (dd, 0.5H, CHHCO2), 2.01 (m, 1H, CH(CH3)2), 1.43 (s, 9H, C(CH3)3), 1.33 (d, 1.5H, CHCH3), 1.27 (d, 1.5H, CHCH3), 0.9 (m, 6H, CH(CH3)2). ##STR34## N-(3-(4-Hydroxyphenyl)-propionyl-valinyl-alaninyl)-4-amino-5-benzyloxy-2-oxotetrahydrofuran

Provenance & Evidence