Trifluoroacetic acid → 5-(2,3-Difluorophenyl)cyclohept-1-ene

Participants

Reaction Steps

In a 250 mL round-bottomed flask (t=g) was added (Z)-1-(2,3-difluorophenyl)cyclohept-4-enol (2.05 g, 9.14 mmol) in CH2Cl2 (40 mL) to give a colorless solution. Triethylsilane (7.30 mL, 45.7 mmol) was added, followed by TFA (20 mL). The mixture was stirred at room temperature for 3 hours: TLC showed a complete conversion (Rf=0.42 by pure hexane). It was concentrated down to a bi-layer oil (the lower layer wasn't hexane-soluble). Purification by FCC using only hexane afforded the desired product as a colorless oil (1.684 g, 88%). 1H NMR (400 MHz, CDCl3) δ 7.00-6.90 (m, 3H), 5.90-5.82 (m, 2H), 3.20-3.05 (m, 1H), 2.40-2.15 (m, 4H), 1.90-1.78 (m, 2H), 1.60-1.40 (m, 2H).

Provenance & Evidence