Reaction #1778

Reaction equation

4-chromanol

diethyl azodicarboxylate

methyl 4-hydroxy-2-methoxybenzoate

triphenylphosphine

→

methyl 4-(4-chromanoyloxy)-2-methoxybenzoate

Solvents

THF

THF

Conditions

Workup

1. 1
   FiltrationThe reaction was filtered
2. 2
   Otherthe solvent was removed under reduced pressure
3. 3
   OtherThe residue was chromatographed on a silica gel column
4. 4
   WashEtOAc and eluted with same
5. 5
   Otherthe solvent removed under reduced pressure

Procedure

To a stirred solution of methyl 4-hydroxy-2-methoxybenzoate (364 mg, 2.0 mmol) in dry THF (1.25 mL) was added triphenylphosphine (525 mg, 2.0 mmol) and the solution was cooled to 0° C. A 500 mL volume of 4-chromanol (200 mg, 1.33 mmol) and diethyl azodicarboxylate (315 mL, 2.0 mmol) in THF was added dropwise via syringe over 0.5 h. The reaction was filtered and the solvent was removed under reduced pressure. The residue was chromatographed on a silica gel column packed in 92:8 hexanes:EtOAc and eluted with same. The appropriate fractions were combined and the solvent removed under reduced pressure to afford methyl 4-(4-chromanoyloxy)-2-methoxybenzoate.

Source