Diazonamide support studies: Stereoselective formation of the C10 chiral center in both the CDEFG and AEFG fragments

The synthesis of both the AEFG macrolactam and the CDEFG bis-indole/tyrosine units found in the marine natural product diazonamide A is presented. Key to the success of the synthesis is the highly stereoselective direct C-arylation of an oxindole by an aryllead(IV) reagent derived from tyrosine.