A Review on the Chemistry of Eremanthine: A Sesquiterpene Lactone with Relevant Biological Activity
Scheme 43
Preparation of the substrates 111, 127, 128, 133, and 140 and subsequent reactions of catalytic hydrogenation as well as methanol addition to α-methylene-γ-lactone of the iodohydrin 111. (a) (i) AcO2H, CHCl3; (ii) KI, AcOH, acetone; (b) Ac2O, pyridine; (c) H2, Pd-C, EtOH; (d) Zn, AcOH, EtOH; (e) (i) MeONa, MeOH; (ii) AcO2H, CH2Cl2; (iii) KI, AcOH, acetone; (f) H2, Pd-C, NaOAc, EtOH; (g) H2, Pt-C, EtOH; (h) MeONa, MeOH.
