Scheme 2.
Reagents and conditions: (a) MsCl, aq. NaHCO3, CH2Cl2, 23 °C, 16 h, 86%; (d) LiOH.H2O, aq. THF, 23 °C, 18 h, 95%; (c) DPPA, Et3N, toluene, 23 °C to reflux, 5 h then aq. NaOH, 98 °C 12 h, 67%; (d) 9, i-PrOH, 56 °C, 14 h, 56-63%; (e) 11a or 11b, aq. NaHCO3, CH2Cl2, 23 °C, 14 h, 90– 98%; (f) Grubbs II, dry CH2Cl2, 40 °C, 3–6 h, 52–92% (E/Z mixture); (g) TFA, CH2Cl2, 23 °C, 48 h; (h) 14, DIPEA, MeCN, 23 °C, 3–7 days, 23–60%; (i) H2, 10 % Pd/C, EtOAc, 23 °C, 12 h, 75–90%.