Total synthesis of γ-trifluoromethylated analogs of goniothalamin and their derivatives

An efficient method for the construction of chiral γ-trifluoromethylated α,β-unsaturated δ-lactone, a widely existing pharmacophore, has been developed and successfully applied for synthesis of γ-trifluoromethylated goniothalamins. The key steps included Evans-Aldol reaction of chiral titanium enolate of α-CF3 imide, Wittig olefination and lactonization. The transformation of γ-trifluoromethylated α,β-unsaturated δ-lactone to a series of trifluoromethylated styryllactones was also investigated.