Removing Part of a Side Chain

Franck and coworkers had previously employed a similar isomerization/CM sequence for the preparation of sugar derivatives used in the synthesis of a-C-galactosyl ceramide immunostimulants, but in their case the isomerization reaction was catalyzed with PdCl2 [28]. 

8-12 hours). Compounds 56b and 56c were then converted into prostaglandins p2a and J2, respectively. It is noteworthy that when catalyst [Ru]-III was used with 54b or 54c, only the homodimers of each partner were obtained. 

There are numerous examples of CM being used to assemble the skeleton of natural products. 

Two Other syntheses of acetogenins involving CM were described in the same year by Crimmins et al. (mucocin) [33] and Hoye et al. (gigantecin) [34]. 

Quinn et al. designed a tandem RCM/CM process for the synthesis of three members of the Annonaceous acetogenin family, muricatacin [39], rollicosin [40], and 

---