반응 #162018

반응 방정식

3β-cholestanol

potassium t-butoxide

propargyl bromide

→

product

3β-(Prop-2-ynyloxy)cholestanol

용매

toluene

hexane

EtOAc

반응 조건

후처리

1. 1
   workup.STIRRINGThe mixture was stirred at r.t. for 3 days
2. 2
   세척washed with water (2×60 mL) and brine (60 mL)
3. 3
   추출The aqueous phase was extracted once with EtOAc (20 mL)
4. 4
   건조The combined organic phases were dried (Na2SO4)
5. 5
   여과filtered
6. 6
   기타the filtrate was evaporated onto silica gel
7. 7
   기타purified by column chromatography (silica gel 2.5×24 cm, gradient elution with hexane 250 mL, hexane-EtOAc 125:5)

실험 절차

3β-cholestanol (1.23 g, 3.16 mmol) was completely dissolved in anhydrous toluene (7 mL, 0.45 M) at r.t. Powdered potassium t-butoxide (1.06 g, 9.49 mmol, 3 eq) was added in one portion. The mixture was stirred at r.t. for 3 h. A solution of propargyl bromide (80 wt % in toluene, 0.94 g, 6.32 mmol, 2 eq) was added. The mixture was stirred at r.t. for 3 days. The mixture was diluted with hexane (30 mL) and EtOAc (10 mL), washed with water (2×60 mL) and brine (60 mL). The aqueous phase was extracted once with EtOAc (20 mL). The combined organic phases were dried (Na2SO4), filtered and the filtrate was evaporated onto silica gel and purified by column chromatography (silica gel 2.5×24 cm, gradient elution with hexane 250 mL, hexane-EtOAc 125:5) to give the product as a yellow solid. Recrystallization from EtOAc (3 mL) gave off-white crystals (736 mg, 55%). 1H NMR (CDCl3, 400 MHz) δ 4.18 (d, 2H, J=2.2), 3.45 (m, 1H), 2.38 (t, 1H, J=2.2), 1.99-0.57 (m, 31H), 0.89 (d, 3H, J=6.6), 0.86 (d, 3H, J=6.6), 0.86 (d, 3H, J=6.6), 0.79 (s, 3H), 0.64 (s, 3H).

출처