Reaction Steps
A solution of 3d (0.118 g, 0.2 mmol) in THF (3 mL) at room temperature was stirred with a solution of n-tetrabutylammonium fluoride in THF (1M, 0.3 mL) for 40 min. The solution was evaporated under vacuum, dissolved in EtOAc (20 mL), dried (Na2SO4) and concentrated. The residue obtained was purified by flash column chromatography over silica gel using hexane:EtOAc (7:3) as eluant to give 3e (0.051 g, 72%) as a white solid; mp 65°-66° C. (EtOAc/hexane); IR (KBr) 3448.1, 1763.2, 1728.1 cm-1 ; 1H NMR (CDCl3) δ 0.88 (distorted t, 3 H, CH3), 1.30 (m, 20 H, CH3 (CH2)10CH2CH2CO); 1.60 (m, 2 H, CH3 (CH2)10CH2CH2CO), 2.00-2.12 (m, 2 H, H-4a), 2.20-2.30 (m, 2 H, H-4b), 2.33 (t, J=7.6 Hz, 2 H, CH3 (CH2)10CH2CH2CO), 2.45 (t, J=6.4 Hz, 1 H, OH), 2.65 (m, 2 H, H-3), 3.60 (dd, J=12.1, 5.9 Hz, 1 H, CHHOH), 3.75 (dd, J=12.1, 6.1 Hz, CHHOH), 4.10 (d, J=12.0 Hz, 1 H, CHHOCO), 4.30 (d, J=12.0 Hz, 1 H, CHHOCO); 13C NMR δ 14.09, 22.65, 24.81, 25.47, 28.79, 29.07, 29.19, 29.32, 29.41, 29.56, 29.60, 31.89, 34.03, 64.82, 65.45, 86.02, 173.48, 176.47; FAB MS (m/z, relative intensity) 357 (MH+, 100), 211 (C13H27CO+, 35). Anal. Calcd for C20H36O5 : C,67.37; H,10.18. Found: C,67.30; H,10.17.
