Biomimetic Synthesis of Chaxine and its Related Compounds

The
highly oxidized natural products chaxine B and BB have been
synthesized from ergosterol in eight steps according to a route inspired
by their proposed biosynthesis; key steps were an oxidative cascade
from a furan intermediate to an enol ester using m-chloroperbenzoic acids (MCPBA), followed by diastereoselective epoxidation
and acyloxy migration. This concise synthesis resulted in the revision
of the structures of chaxine B and its naturally occurring analogs
and syntheses of the unnatural analogues of these natural products
for biological investigations.