The Hoveyda Synthesis of - -Clavirolide

Addition of n-BuLi to 2 regenerated the enolate. There were two issues in the addition of that enolate to the aldehyde 7 syn vs. anti stereocontrol, and control of the configuration of the newly formed ternary center on the ring relative to the abeady-estahUshed quaternary center. Inclusion of Et,B in the reaction mixture assured anti aldol formation, hut there was 

This concise synthesis of the dolabellane 3 showcases the power of the catalytic enanti-oselective methods for the construction of both ternary and quaternary, including cyclic quaternary, centers that Professor Hoveyda has developed. Clearly, asymmetric transformation of inexpensive prochiral ring precursors such as 1 and 4 will make advanced, high ee intermediates such as 2 and 5 much more leadUy available than they have been in the past. 

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