2861-28-1

6006-82-2

6.2.1 Synthesis of 2-(1,3-benzodioxol-5-yl)ethanol (21) [9]. A solution of anhydrous THF (10 mL) with acid 20 (3.00 mmol) was slowly added dropwise to a suspension of anhydrous THF (20 mL) with lithium aluminum hydride (0.114 g, 3.00 mmol) over 15 min. After 4 h of reaction, methanol (1 mL) and 10% NaOH aqueous solution (2 mL) were added sequentially to quench the excess reducing agent until aluminum hydroxide precipitate was formed. Subsequently, the reaction mixture was neutralized with 10% aqueous hydrochloric acid solution (about 5 mL). The resulting mixture was extracted with ethyl acetate (3 x 15 mL), and the combined organic phases were washed with brine, concentrated under reduced pressure, and dried over anhydrous sodium sulfate. The residue was purified by silica gel column chromatography (eluent: CHCl3/EtOH = 100:1) to afford the target product, sterol 21, as a yellow oil in a yield of 0.489 g (98%). Thin layer chromatography (TLC) Rf = 0.5 (CHCl3/EtOH = 20:1). IR (thin film, cm-1): 3351, 2883, 1607, 1503, 1489, 1442, 1247, 1040. 1H NMR (CDCl3): δ 1.87 (br, 1H, ArCH2CH2OH); 2.76 (t, J = 6.5 Hz, 2H, ArCH2CH2OH); 3.78 (t, J = 6.5 Hz, 2H, ArCH2CH2OH); 5.91 (s, 2H, OCH2O); 6.65 (dd, J = 7.8 Hz, J = 1.6 Hz, 1H, 4'); 6.71-6.70 (m, 1H, 2'); 6.75 (d, J = 7.8 Hz, 1H, 5').13C NMR (CDCl3): δ 38.6 (ArCH2CH2OH); 63.5 (ArCH2CH2OH); 100.6 (OCH2O); 108.1 (CH, 2'); 109.1 (CH, 5'); 121.7 (CH, 6'); 132.0 (C, 1'); 145.9 (CH, 4'); 147.5 (CH, 3').