Reaktion #57066

Reaktionsgleichung

MeOH

water

furan

BuLi

PhMe

→

25

Ausbeute 54.0%

5,8-epoxy-5,8-dihydronaphtho[2,3-d][1,3]dioxole

Ausbeute 54.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to rt
2. 2
   workup.WAITAfter 3 hours
3. 3
   SonstigeThe organic layer was separated
4. 4
   Extraktionthe aqueous layer was extracted three times with Et2O
5. 5
   WaschenThe combined organic layers were washed with brine
6. 6
   Trocknendried over MgSO4
7. 7
   Einengenconcentrated
8. 8
   SonstigeRecrystallization from hexanes

Vorschrift

To 3,4-dibromobenzo-1,3-dioxolane (1.54 g, 5.50 mmol) and furan (4 g, 58.8 mmol) in PhMe (55 mL) at −78° C. was added BuLi (2.2 mL, 2.5M in hexanes, 5.5 mmol) dropwise. The reaction was stirred for two hours at −78° C. and the allowed to warm to rt. After 3 hours, MeOH (2 mL) was added and the reaction mixture was poured into water. The organic layer was separated and the aqueous layer was extracted three times with Et2O. The combined organic layers were washed with brine, dried over MgSO4, and concentrated. Recrystallization from hexanes gave 25 (560 mg, 54%) as white crystals). Rf=0.47 on silica gel (30% ethyl acetate:hexanes); mp 111-112° C. (Et2O); IR (KBr, cm−1) 2895, 1455, 1292, 1138, 1038, 1014, 848; 1H NMR (400 MHz, CDCl3) δ 7.02 (2H, dd, J=0.9, 0.9 Hz), 6.82 (2H, s), 5.92 (1H, d, J=1.5 Hz), 5.87 (1H, d, J=1.5 Hz), 5.62 (2H, s); 13C NMR (400 MHz, CDCl3) δ 144.3, 143.3, 103.9, 101.1, 82.4. HRMS calcd for C11H02 (M+): 188.0473. Found: 188.0463.

Quelle