Reaction Steps
DMAP (8.1 mg, 0.06 mmol) and succinic anhydride (67 mg, 0.67 mmol) were added to a stirred solution of derivative 16 (0.35 g, 0.67 mmol) in dry pyridine (5 mL) and the resulting mixture was stirred for 16 h at rt under argon. After that, myristoyl chloride (0.21 ml, 0.80 mmol) was added dropwise, and the reaction mixture was stirred for 2 h at rt. After that, the resulting mixture was concentrated under the reduced pressure. The residue was dissolved in CH2Cl2 (30 mL) and washed successively with 1N HCl (2×15 mL), water (2×15 mL) and brine (15 mL). The organic phase was separated, dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by column chromatography on silica gel (ethyl acetate-hexane gradient elution) to give compound 17 (0.43 g, 0.52 mmol) as white syrup in 79% yield. Analytical data for 17: Rf=0.55 (ethyl acetate-hexane 1/1, v/v); [α]D24+42.4° (c=1.0, CHCl3); 1H NMR (300 MHz, CDCl3): δ, 0.87 (t, 6H, 2×CH3), 1.25 (br. s, 40H, 20×CH2), 1.59 (m, 4H, 2×CH2), 2.26 (m, 2H, CH2), 2.33 (m, 2H, CH2), 2.61 (m, 4H, 2×CH2), 3.36 (s, 3H, OCH3), 3.59 (dd, 1H, J4,5=9.5 Hz, H-4), 3.90 (m, 1H, H-5), 4.28 (dd, 2H, J5,6b=4.4 Hz, J6a,6b=11.5 Hz, H-6a, 6b), 4.44 (d, 1H, J2=10.7 Hz, ½CH2Ph), 4.54 (d, 1H, J2=10.7, ½CH2Ph), 4.87 (m, 2H, H-1, 2), 5.55 (dd, 1H, J3,4=9.5 Hz, H-3), 6.84 (d, 2H, J=8.7 Hz, aromatic), 7.16 (d, 2H, J=8.6 Hz, aromatic) ppm; 13C NMR (75 MHz, CDCl3): δ, 14.3, 22.8, 25.1, 28.8, 29.2, 29.3, 29.4 (×2), 29.5, 29.6, 29.7, 29.8, 32.1, 34.2, 34.5 (×3), 55.4, 62.7, 68.6, 71.8, 71.9, 74.3, 75.7, 96.9, 114.0, 129.5, 129.8, 159.6, 171.7, 172.8, 173.7 ppm; HR FAB MS [M+Na]+ calcd for C47H78O12Na 857.5391. found 857.5410.
