Total synthesis of sphingofungin F based on chiral tricyclic iminolactone.

A new, efficient synthesis of sphingofungin F has been accomplished with 10.4% overall yield in 15 steps. The salient features of the synthesis are the utilization of methyl tricyclic iminolactone 3 for the asymmetric aldol reaction as a key step to introduce two desired stereogenic centers, one-pot reaction for the synthesis of omega-hydroxyketone from epsilon-caprolactone, and an effective one-step deprotection strategy to remove all protecting groups using 0.2 N HCl.