Abstract: A highly stereoselective Claisen rearrangement of allyl vinyl ether 17 gives rise to@-keto ester 18 having the correct relative stereochemistry at Cg, Cp, and C14 of the quassinoids. Efficient, rapid assembly of rings C, D, and E is achieved. The model sets the stage for an eventual synthesis of (-)-bruceantin from keto acid 9b.