Reaction #2320149

Reaction equation

methanol

borane tetrahydrofuran

2,3-Dihydrobenzofuran carboxylic acid

borane tetrahydrofuran

→

title compound

2,3-dihydro-1-benzofuran-7-ylmethanol

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   TemperatureThe mixture was cooled to 5° C.
2. 2
   Concentrationconcentrated under reduced pressure
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   Washwashed with saturated sodium bicarbonate (2×), saturated sodium chloride
5. 5
   Dryingdried (sodium sulfate)
6. 6
   Filtrationfiltered
7. 7
   Concentrationthe filtrate was concentrated under reduced pressure
8. 8
   OtherThe residue was purified by flash chromatography (hexanes:ethyl acetate, 3:2)

Procedure

2,3-Dihydrobenzofuran carboxylic acid (5.047 g, 30.77 mmol) in tetrahydrofuran at −10° C. was treated dropwise with a solution of 1.0 M borane-tetrahydrofuran (20 mL 20 mmol). The temperature was allowed to warm to room temperature overnight, and was then treated with additional 1.0 M borane-tetrahydrofuran (10 mL 10 mmol), and stirred at room temperature for 2 hours. The mixture was cooled to 5° C., slowly treated with methanol (20 mL), and concentrated under reduced pressure. The residue was dissolved in ethyl acetate, washed with saturated sodium bicarbonate (2×), saturated sodium chloride, dried (sodium sulfate), filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by flash chromatography (hexanes:ethyl acetate, 3:2) to provide the title compound. MS (DCI/NH3) M/Z 168 (M+NH4)+; 1H NMR (CDCl3) δ 3.21 (t, 2H), 4.60 (t, 2H), 4.68 (s, 2H), 6.83 (t, 1H), 7.08 (dd, 1H), 7.14 (dd, 1H).

Source