Lanthanide(III) Promoted Aldol Condensation of Enones and Aldehydes¹

References and Notes

• Dedicated to Professor J. D. Winkler, an inspiring teacher to whom we are very grateful.
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• (a) Excess MVK enolate and/or lanthanides did not improve the yield.
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• All new compounds were characterized by full spectroscopic data (1H, 13C NMR, IR, MS, and HRMS). Yields refer to spectroscopically and chromatographically purified (>95%) materials.
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• This is true even in the case of aldehydes which give very low yields of 1,2-addition products in the presence of alkyl lithium or Grignard reagents, see: Imamoto T. Kusumoto T. Yokoyama M. J.C.S. Chem. Comm. 1982 1042
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• Kobayashi , S. and Hachiya , I. 1994 . J. Org. Chem. , 59 : 3590 We have also tried the reaction of the MVK enol silyl ether with aldehydes and Yb(OTf)3 via the typical Kobayashi method and the reaction yielded only 25% of the desired aldol adduct. For the typical Kobayashi reaction, see:
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