Tetrahydrofuran → N-(9-fluorenylmethoxycarbonyl)-O-(4,4-bis(diethylphosphoryl)butyl)-L-tyrosine

Beteiligte Stoffe

Reaktionsschritte

A solution of 83 (664 mg, 1.44 mmol) and PPh3 (454 mg, 1.73 mmol) in THF (20 mL) was cooled in an ice-bath followed by the addition of diisopropyl azodicarboxylate (336 mg, 1.74 mmol). After a further 10 min a solution of 81 (500 mg, 1.44 mmol) in THF (5 mL) was added and the resulting solution was stirred while warming to room temperature overnight. The solvent was removed at reduced pressure and the crude material was purified by silica gel chromatography (0 to 10% methanol in ethyl acetate over 10 column volumes then 10 to 20% over 5 column volumes) using a Biotage Horizon™ apparatus resulting in the colourless liquid 84 (491 mg, 43%): 1H NMR (400 MHz, CDCl3) δ 1.33 (t, J=7.1, 6H), 1.34 (t, J=7.1, 6H), 1.43 (s, 9H), 2.04-2.18 (m, 4H), 2.37 (tt, J=6.3, 24.2, 1H), 2.98-3.07 (m, 2H), 3.92 (t, J=5.8, 2H), 4.14-4.22 (m, 8H), 4.33 (dd, J=7.1, 10.4, 1H), 4.43 (dd, J=7.2, 10.5, 1H), 4.50 (dd, J=6.0, 8.4, 1H), 5.24, (d, J=8.1, 1H), 6.78 (d, J=8.5, 2H), 7.04 (d, J=8.4, 2H), 7.28-7.33 (m, 2H), 7.40 (t, J=7.6, 2H), 7.77 (d, J=7.6, 2H): 31P (162 MHz, CDCl3) δ 24.74 (s, 2P).

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