Synthesis of γ-Trifluoromethyl Tetronate Derivatives from Squarates
摘要:
Squarates and semisquarates were treated with TMSCF3 in the presence of a catalytic amount of AcONa in DMF at room temperature to afford 4-trifluoromethyl-4-hydroxycyclobutenones. Subsequent oxidative ring expansion of these products was performed using Pb(OAc)(4) in the presence of MS 4A in 1,2-dichloroethane at 50 degrees C to afford gamma-trifluoromethyl tetronate derivatives.