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Three-component glycolate Michael reactions of enolates, silyl glyoxylates, and ?,?-enones.

ABSTRACT: Silyl glyoxylates react with enolates and enones to afford either glycolate aldol or Michael adducts. Product identity is controlled by the countercation associated with the enolate. Reformatsky nucleophiles in the presence of additional Zn(OTf)(2) result in aldol coupling (A), while lithium enolates provide the Michael coupling (B). Deprotonation of the aldol product A with LDA induces equilibration to form the minor diastereomer of Michael product B. This observation suggests that formation of the major diastereomer of Michael product B does not occur via an aldol/retro-aldol/Michael sequence.

SUBMITTER: Schmitt DC

PROVIDER: S-EPMC3321131 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

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Three-component glycolate Michael reactions of enolates, silyl glyoxylates, and α,β-enones.

Schmitt Daniel C DC Malow Ericka J EJ Johnson Jeffrey S JS

The Journal of organic chemistry 20120315 7

Silyl glyoxylates react with enolates and enones to afford either glycolate aldol or Michael adducts. Product identity is controlled by the countercation associated with the enolate. Reformatsky nucleophiles in the presence of additional Zn(OTf)(2) result in aldol coupling (A), while lithium enolates provide the Michael coupling (B). Deprotonation of the aldol product A with LDA induces equilibration to form the minor diastereomer of Michael product B. This observation suggests that formation of ...[more]

PMID: 22394389

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