170196.sch.0039
Scheme 39: Syntheses of the substrates 85, 130, 154, and 156158 and their epimers at C-6 positions (159165). (a) MeONa, MeOH; (b) (i) AcO2H, CH2Cl2; (ii) KI, AcOH, acetone; (iii) H2, Pd-C, NaOAc, EtOH; (c) NaOH-H2O, DMF; (d) Ac2O, pyridine; (e) H2, Pd-C, EtOH; (f) BF3.OEt2, benzene; (g) (i) AcO2H, CHCl3; (ii) KI, AcOH, acetone; (h) Zn, AcOH, EtOH; (i) (i) KOH-H2O (ii) Dryness; (iii) MsCl, Et3N, DMSO; (iv) NaOH-H2O; (v) HCl-H2O; (j) (i) KOH-H2O (ii) Dryness; (iii) MsCl, Et3N, THF; (iv) NaOH-H2O; (v) HCl-H2O.