The synthesis of the pseudopterosin A–F aglycone from 3-methylcatechol features (a) the use of asymmetric Ireland–Claisen and aryl Claisen rearrangements to install three of the four stereocentres present in the molecule and (b) an A→AB→ABC annulation strategy using ring-closing metathesis and cationic cyclisation reactions as the key steps.
Key words
total synthesis - terpenoids - ring closure - rearrangement - metathesis - pericyclic reaction