Abstract
β,γ-Unsaturated aldehydes with all-carbon quaternary or tertiary α-centers were rapidly assembled from ketones through a unique synthetic operation consisting of 1) C 1 homologation, 2) Lewis acid mediated epoxide–aldehyde isomerization, and 3) electrophilic trapping. The synthetic equivalence of a vinyl oxirane and a β,γ-unsaturated aldehyde is the key concept of this previously undisclosed tactic. Mechanistic studies and labeling experiments suggest that an aldehyde enolate is a crucial intermediate. The homologating carbenoid formation plays a critical role in determining the chemoselectivity.
Original language | English |
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Pages (from-to) | 12677-12682 |
Number of pages | 6 |
Journal | Angewandte Chemie (International Edition) |
Volume | 56 |
Issue number | 41 |
DOIs | |
Publication status | Published - 2 Oct 2017 |
Austrian Fields of Science 2012
- 104001 General chemistry
Keywords
- ALLYLATION
- ALLYLIC ALCOHOLS
- BETA,GAMMA-UNSATURATED ALDEHYDES
- BRANCHED ALDEHYDES
- CHEMOSELECTIVE ADDITION
- ENANTIOSELECTIVE CONSTRUCTION
- LITHIUM CARBENOIDS
- PI-METHANE REARRANGEMENT
- STEREOGENIC CENTERS
- SYNTHETIC EQUIVALENTS
- aldehydes
- carbenoids
- enolates
- homologation
- isomerization