Reaction Steps
Compound BC4 (0.2 g, 0.2 mmol) was dissolved in 50:50 THF/MeOH (20 mL), and following addition of 3 mL conc. HCl to the flask, the mixture was heated to reflux for 6 hours. The mixture was let to cool to room temperature, diluted with water (10 mL), and extracted with CH2Cl2 (2×200 mL). The solvent was removed, and the residue purified by column chromatography (CH2Cl2: EtOH, 10:0.03). The product was then selectively precipitated from CH2Cl2 through dropwise addition of petroleum ether. Yield 0.11 g (60%). EA: Found: C, 69.37; H, 7.21. C56H66O10S2 requires C, 69.83; H, 6.91%. 1H NMR: δH (CDCl3; 300 MHz): 1.24-1.56 (30 H, m, CH2 / SH), 1.63 (4 H, m, S—CH2—CH2), 1.85 (4 H, m, O—CH2—CH2), 2.55 (4 H, q, 3J=7.4, SCH2), 4.07 (4 H, t, 3J=6.5 Hz, OCH2), 7.01 (4 H, d, 3J=8.9 Hz, Ar—H), 7.22 (3 H, m, Ar—H), 7.40 (4 H, d, 3J=8.7 Hz, Ar—H), 7.50 (1 H, t, 3J=8.2 Hz, Ar—H), 8.17 (4 H, d, 3J=8.9 Hz, Ar—H), 8.29 (4 H, d, 3J=8.7 Hz, Ar—H). 13C NMR: δC (CDCl3; 75 MHz): 25.1, 26.4, 28.8, 29.5, 29.7, 29.9, 29.9, 34.4, 53.8, 68.8, 114.8, 116.2, 119.7, 121.4, 122.5, 127.0, 130.3, 132.3, 132.8, 151.8, 155.9, 164.2, 164.5, 164.7. m/z (MALDI) 985.81 [M+Na]+, C56H66NaO10S2 requires 985.40.
