Fig. 5: Syntheses of (–)-germine (2) and (–)-protoverine (3). | Nature Communications

Fig. 5: Syntheses of (–)-germine (2) and (–)-protoverine (3).

From: Divergent syntheses of complex Veratrum alkaloids

Fig. 5

Reagents and conditions: a nBu3SnH, AIBN, benzene, reflux, 1.5 h then BOMCl, TBAI, DIPEA, DCE, 80 °C, 2 h then TBAF, THF, reflux, 3 h, 89%. b DMP, NaHCO3, DCM, 30 °C, 13 h, 72%. c Pd(OH)2/C, MeOH, H2 (1 atm), rt, 5 h. d Et2SiH2, [Ir(COE)2Cl]2, toluene, reflux, 3 h then MeCN, HF (40% aq.), rt, overnight, 45% (2 steps). e TEMPO, nBu3SnH, toluene, reflux, 3 h, 87%. f UHP, Na2CO3, TFAA, DCM, 0 °C, 6 h, 81%. g NaBH4, MeOH, 0 °C, 30 min, 85%. h BOMCl, TBAI, DIPEA, DCE, 80 °C, 2 h, then TBAF, THF, reflux, 3 h, 81%. i DMP, NaHCO3, DCM, 30 °C, 14 h, 78%. j Pd(OH)2/C, MeOH, H2 (1 atm), rt, 5 h. k Et2SiH2, [Ir(COE)2Cl]2, toluene, reflux, 3 h then MeCN, HF (40% aq.), rt, overnight, 53% (2 steps). UHP, urea hydrogen peroxide; TFAA, trifluoroacetic anhydride.

Back to article page