A tandem non-aldol aldol Mukaiyama aldol reaction.
[reaction: see text] A new one-pot tandem aldol process is described in which a secondary epoxy silyl ether is converted into the 1,5-bis-silyloxy-3-alkanone in good yield. Thus, treatment of the epoxy silyl ether 8 with TBSOTf and base affords the silyl enol ether 9 via non-aldol aldol rearrangement and addition of benzaldehyde and TBSOTf gives the ketone 10 with 4:1 syn selectivity. The diastereoselectivity changes to an anti preference for most aldehydes. This anti selectivity overwhelms the normal Felkin-Ahn preference; namely, the 1,5-anti isomer predominates even when it is anti-Felkin-Ahn.
Jung
Michael E
ME
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA. jung@chem.ucla.edu
van den Heuvel
Alexandra
A
D000447:Aldehydes / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry; D004987:Ethers / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D015394:Molecular Structure; D012821:Silanes / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D004852:Epoxy Compounds; D004987:Ethers; D007659:Ketones; D012821:Silanes; C116609:3-hydroxybutanal