Imidazole → HCID 9985234, compound

Participants

Reaction Steps

Compound 2002 (7.6 g, 17 mmol) in dry CH2Cl2 (300 ml) was treated with a solution of t-butyldimethylsilylchloride (TBDMSCl, 1.0M) and imidazole (0.5M) in dry CH2Cl2 (38.0 ml, 38.0 mmol TBDMSCl). The solution was stirred at room temperature under argon overnight. The resultant solution was poured into an aqueous saturated NaHCO3 solution and the mixture extracted with CH2Cl2 (3×). The combined organic layers were washed with saturated sodium chloride, dried over anhydrous MgSO4, filtered, and the solvent removed in vacuo. The resultant solid was purified by flash chromatography (SiO2, hexanes:EtOAc gradient from 20:1 to 5:1) giving compound 2003 (9.4 g, 17 mmol, 98%). 1H NMR (500 MHz, CDCl3) δ: 5.38-5.32 (m, 1H, C-6 H), 4.72 (brs, 1H, THP methine H), 3.95-3.88 (m, 1H, THP CH2O), 3.60-3.46 (m, 4H THP CH2O & C-3 H & C-24 H), 1.01 (s, 3H, C-19 H), 0.93 (d, J=6.6 Hz, C-21 H), 0.89 (s, 9H, t-Bu), 0.67 (s, 3H, C-18 H), 0.05 (s, 6H, TBDMS CH3); IR (CHCl3) 2900 cm-1 ; MS (CI/isobutane) m/z 559 (M+1, 1%), 474 (M+1-THP, 12%), 457 (M+1-THPOH, 18%), 343 (M+1-THP-TBDMSOH, 6%), 325 (M+1-THPOH-TBDMSOH, 100%); m.p. 116°-118° C.; Anal. calcd. for C35H62O3Si: C=75.21, H=11.18; Found: C=75.37, H=11.24.

Provenance & Evidence