The role of β-bulky alkyl substituents in aldol reactions of boron enolates of methylketones with aldehydes

The role of β-bulky alkyl substituents in aldol reactions of boron enolates of methylketones with aldehydes

Júnior, Emílio Carlos de Lucca; Dias, Luiz Carlos

Abstract:

Recently, we described that the levels of 1,5-syn selectivities in aldol reactions involving boron enolates of -alkoxy methylketones, where the - alkoxy protecting group is TBS, are dependent on the volume of the alkyl substituent in -position (Scheme 1). Based on these results, we prepared methylketone 5 in order to assess the steric contribution of the β-alkyl substituent in reactions of the corresponding boron enolates with achiral aldehydes.

Recently, we described that the levels of 1,5-syn selectivities in aldol reactions involving boron enolates of -alkoxy methylketones, where the - alkoxy protecting group is TBS, are dependent on the volume of the alkyl substituent in -position (Scheme 1). Based on these results, we prepared methylketone 5 in order to assess the steric contribution of the β-alkyl substituent in reactions of the corresponding boron enolates with achiral aldehydes.

Palavras-chave:

DOI: 10.5151/chempro-14bmos-R0086-1

Referências bibliográficas

• [1] 1 Dias, L. C.; Marchi, A. A.; Ferreira, M. A. B.; Aguilar, A. M. J. Org. Chem. 2008, 73, 6299.
• [2] 2 Paterson, I.; Gibson, K. R.; Oballa, R. M. Tetrahedron Lett. 1996, 37, 8585.
• [3] 3 Evans, D. A.; Coleman, P. J.; Côté, B. J. Org. Chem. 1997, 62, 788.
• [4] 4 Dias, L. C.; de Lucca Jr., E. C.; Ferreira, M. A. B.; Garcia, D. C.; Tormena, C. F. Org. Lett. 2010, 12, 5056.
• [5] 5 Kobayashi, Y.; Tan, C.-H.; Kishi, Y. Helv. Chim. Acta 2000, 83, 2562.

Como citar:

Júnior, Emílio Carlos de Lucca; Dias, Luiz Carlos; "The role of β-bulky alkyl substituents in aldol reactions of boron enolates of methylketones with aldehydes", p-86-86. In: In Blucher Chemistry Proceedings, São Paulo, v. 1, n. 1, Setembro.2013. São Paulo: Blucher, 2013.
ISSN 23184043, DOI 10.5151/chempro-14bmos-R0086-1