Cemuane-Type Alkaloids

Fig. 8 Divergent strategy for the total syntheses of cemuane-type and quinolizidine-type Lycopodium alkaloids...

Next, we performed the syntheses of cemuane-type alkaloids, cermizine D (90) and cemuine (86), from common key intermediate 91 (Scheme 19). The primary alcohol in 91 was oxidized with IBX to give the aldehyde, which, in turn, was subjected to the Wittig reaction without purification to afford 102. Mild acid... 

Morita H, Hirasawa Y, Shinzato T, Kobayashi J (2004) New phlegmarane-type, cemuane-type, and quinolizidine alkaloids from two species of Lycopodium. Tetrahedron 60 7015-7023... 

Nishikawa Y, Kitajima M, Kogure N, Takayama H (2009) A divergent approach for the total syntheses of cemuane-type and quinolizidine-type Lycopodium alkaloids. Tetrahedron 65 1608-1617... 

Nishikawa Y, Kitajima M, Takayama H (2008) First Asymmetric Total Syntheses of Cemuane-Type Lycopodium Alkaloids, Cemuine, and Comizine D. Org Lett 10 1987... 

Finally, the first total syntheses of two cemuane-type Lycopodium alkaloids, ( )-cernuine and (+)-cermizine D, reported by Takayama et al., included as a key step a L-proline-catalysed amination of an aldehyde derived from (+)-citronellal. As shown in Scheme 4.4, this amination performed with dibenzyl azodicarboxylate, followed by an in-situ reduction with NaBH4 and treatment of the resulting mixture with K2CO3, furnished the expected oxazolidinone in a high yield and a good diastereoselectivity. 

---