An improved general syntehtic approach to cis-clerodane diterpenoids.A more efficient total synthesis of (+-)-6#beta#-acetoxy-2-oxokolavenool

摘要

The previously developed general synthetic approach to cis-clerodane diterpenoids has been greatly improved using 4-(2-benzyloxy)ethyl-2-cyano-4-methyl-2,5-cyclohexadien-1-one (4) as the starting dienophile.This approach allows the direct incorporation of an angular methyl group via reductive alkylation of the #alpha#-cyano ketone system.The viability of this approach to cis-clerodanes has been demonstrated in the alternative total synthesis of (+-)-6#beta#-acetoxy-2-oxokolavenool (1).