Scheme 3. Synthesis and failed difluorocyclopropanation of 2-furyl allyl acetate 14a. Conditions: (i) (carbethoxymethylene)-triphenylphosphorane (1.1 eq.), DCM, r.t., 17 h (ii) DIBAL (3 eq.), toluene, –78 °C to r.t., 8 h (iii) Ac2O (1.2 eq.), pyridine (1.2 eq.), DCM, 45 °C, 5 h (iv) MDFA (2.5 eq.), TMSCl (2.5 eq.), KI (2.8 eq.), diglyme (1.17 eq.), 120 °C, 24 h.
