Simmons-Smith reaction annulation

An unusual combination, namely a Michael addition and a Simmons-Smith reaction, has been elaborated by the group of Alexakis [112]. Using their protocol, 3/5-as well as 3/6-annulated systems can easily be obtained, which might be useful as precursors for the total syntheses of (-)-(S,S)-clavukerin A and (+)-(R,S)-iso-clavukerin, both isolated from Clavularia koellikeri [113]. 

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