Formic Acid → HCID 72483450, compound

Reaction equation

[CH2:1]([O:3][C:4]1[CH:19]=[CH:18][C:7]2[CH:8]3[CH2:14][CH2:13][C:12](=[CH:15][O:16]C)[CH2:11][CH:9]3[O:10][C:6]=2[C:5]=1[F:20])[CH3:2].C(O)=O.O>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]1[CH:19]=[CH:18][C:7]2[CH:8]3[CH2:14][CH2:13][CH:12]([CH:15]=[O:16])[CH2:11][CH:9]3[O:10][C:6]=2[C:5]=1[F:20])[CH3:2]

Participants

Procedure

8.0 g (28.7 mmol) of (±)-(4aR*, 9bS*)-7-ethoxy-6-fluoro-3-[1-methoxy-methylidene]-1,2,3,4,4a,9b-hexahydrodibenzofuran are dissolved in 200 ml of toluene and stirred vigorously at room temperature for 18 h together with 30 ml (0.80 mol) of formic acid and 0.5 ml (27.8 mmol) of water. The organic phase is separated off and washed successively with water, sat. sodium hydrogencarbonate solution and sat. sodium chloride solution. The solution is dried using sodium sulfate and concentrated to dryness. Purification by column chromatography (SiO2, toluene:ethyl acetate=99:1) gives a mixture (64:36) of (±)-(3R*, 4aR*, 9bS*)-7-ethoxy-6-fluoro-1,2,3,4,4a,9b-hexahydrodibenzofuran-3-carbaldehyde and (±)-(3S*, 4aR*, 9bS*)-7-ethoxy-6-fluoro-1,2,3,4,4a,9b-hexahydrodibenzofuran-3-carbaldehyde.