Trifluoroacetic acid → 2-(1-Methylcyclopropyl)-4H-pyran-4-one

Participants

Reaction Steps

A mixture of 1-hydroxy-5-methoxy-1-(1-methyl-cyclopropyl)-penta-1,4-dien-3-one (Step 40.7) (1.07 g, 5.9 mmol) and TFA (0.9 mL, 11.7 mmol, 2 eq) in toluene (50 mL) is stirred for 14 h at rt and concentrated. Purification of the residue by silica gel column chromatography (Hex/EtOAc, 1:0→3:7) provides 442 mg of the title compound as a red solid: ESI-MS: 151.1 [M+H]+; tR=2.89 min (System 1); TLC: Rf=0.19 (Hex/EtOAc, 1:1).

Provenance & Evidence