Ileabethane, pseudopterane or nor-sandresane diterpenoids
Description:
Diterpenoids with a structure based on either the ileabethane, the pseudopterane, or the nor-sandresane skeleton. Ileabethane is a tricyclic carbon skeleton arising from the C8-C14 of serrulatane. In the nor-sandresane skeleton, a cyclohexane ring is fused to a seven-membered saturated aliphatic carbocycle, which could stem from the rearrangement of an amphilectane-based precursor involving loss of a carbon atom and a 1,2-alkyl shift with ring expansion.