Skip to main content
. Author manuscript; available in PMC: 2011 May 19.
Published in final edited form as: J Am Chem Soc. 2010 May 19;132(19):6855–6861. doi: 10.1021/ja102260q

Scheme 6. Completion of the Synthesis of the Maitotoxin ABCDEFG Ring System 3a.

Scheme 6

aReagents and conditions: (a) PPTS (0.5 equiv), CH2Cl2:MeOH (10:1), 0 °C, 1 h, 88%; (b) NMO (3.0 equiv), TPAP (0.1 equiv), 4 Å MS, CH2Cl2:MeCN (9:1), 25 °C, 30 min, 78%; (c) (MeO)2P(O)CH3 (5.0 equiv), n-BuLi (2.5 M in hexanes, 5.0 equiv), THF, −78 °C, 1 h; then 40 (1.0 equiv), −78 °C, 2.5 h; (d) DMP (3.0 equiv), CH2Cl2, 25 °C, 30 min, 66% over the two steps plus 17% recovered starting material (40); (e) i-Pr2NEt (3.0 equiv), LiCl (3.0 equiv), 4 (1.4 equiv), MeCN, 25 °C, 72 h, 91% (95% brsm); (f) TsOH (3.0 equiv), MeOH:CH2Cl2 (3:1), 25 °C, 2 h; (g) Et3SiH (10.0 equiv), TMSOTf (5.0 equiv), MeCN, −40 → −25 °C, 30 min, 69% over the two steps; (h) NMO (3.0 equiv), OsO4 (2.5 wt % in t-BuOH, 0.05 equiv), acetone:H2O (4:1), 72 h, 61%, plus 26% of the opposite diastereomer; (i) 20% Pd(OH)2/C (50% w/w), H2, EtOH, 6 d, 97%.