Reaktion #485275

Reaktionsgleichung

allyl ether

5-(allyloxy)-1,3-dihydro-2-benzothiophene

sodium borohydride

→

1,3-dihydro-2-benzothiophen-5-ol

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas evaporated
2. 2
   Sonstigethe residue partitioned between 2M NaOH solution (25 mL) and diethyl ether (25 mL)
3. 3
   SonstigeThe aqueous layer was separated
4. 4
   Extraktionthe organic layer re-extracted with 2M NaOH solution (25 mL)
5. 5
   Extraktionextracted with EtOAc (2×25 mL)
6. 6
   TrocknenThe combined organic extracts were dried (MgSO4)
7. 7
   Sonstigeevaporated to a clear oil of the title phenol which

Vorschrift

The allyl ether from stage (ii) (800 mg, 4.16 mmol) was dissolved in THF (10 mL) and treated with palladium tetrakis(triphenylphosphine) (481 mg, 0.42 mmol) followed by sodium borohydride (944 mg, 25 mmol). The mixture was then heated to 45° C. and stirred at this temperature for 15 h. After cooling to room temperature the THF was evaporated and the residue partitioned between 2M NaOH solution (25 mL) and diethyl ether (25 mL). The aqueous layer was separated and the organic layer re-extracted with 2M NaOH solution (25 mL). The combined aqueous layers were neutralised to pH 7-8 with concentrated hydrochloric acid and extracted with EtOAc (2×25 mL). The combined organic extracts were dried (MgSO4) and evaporated to a clear oil of the title phenol which solidified upon standing (540 mg, 85%); 4.14 (2H, s), 4.17 (2H, s), 6.63-6.68 (2H, m), 7.04 (1H, d).

Quelle