Reaction Steps
A solution of carbonate 16 (0.15 g, 0.28 mmol) in DMF (approximately 2 mL) was added to a solution of Et3N (0.5 g, 4.95 mmol) and N-Boc-N′-biotinyl-3,6-dioxaoctane-1,8-diamine (Ning et al., Angew. Chem. Int. Ed. 2008, 47:2253-2255) (0.01 g, 0.28 mmol) in DMF (10 mL) at room temperature. The reaction mixture was stirred overnight at room temperature, most solvent was evaporated under reduced pressure, and the residue was separated by chromatography on (CH2Cl2:MeOH 30:1) to provide 0.164 g (0.21 mmol, 75%) of 6b. 1H NMR δ 7.19 (d, J=8.4 Hz, 2H), 6.88 (dd, J=9.5, 2.5 Hz, 2H), 6.76 (td, J=8.2, 2.5, 2H), 6.74-6.65 (m, 1H), 6.54 (s, b, 1H), 5.74 (s, b, 1H), 5.60 (s, b 1H), 4.49-4.43 (m, 1H), 4.29-4.22 (m, 3H), 4.16-4.10 (m, 2H), 3.97 (t, J=6.5, 2H), 3.87-3.81 (m, 2H), 3.76 (m, 2H), 3.59-3.48 (m, 7H), 3.42 (m, 2H), 3.37-3.12 (m, 2H), 3.21-3.09 (m, 4H), 2.86 (dd, J=12.6, 4.7 Hz, 1H), 2.72 (d, J=12.7, 1H), 2.42 (d, J=10.9, 2H), 2.21 (t, J=7.4, 2H), 1.81-1.56 (m, 5H), 1.48 (sex, J=7.4 Hz, 2H), 1.44-1.36 (m, 2H), 1.32 (t, J=7.4 Hz, 1H), 0.98 (t, J=7.4, 3H); 13C NMR δ 173.4, 164.1, 158.7, 158.1, 156.5, 154.8, 126.66, 126.63, 116.80, 116.72, 116.59, 115.8, 111.91, 111.83, 110.67, 110.14, 70.09, 70.04, 69.95, 69.90, 69.80, 69.54, 67.78, 67.52, 63.88, 61.80, 60.2, 55.6, 45.6, 40.8, 40.5, 39.1, 36.63, 36.61, 35.9, 31.3, 28.22, 28.08, 25.6, 19.2, 13.8, 8.5.
