Abstract
Abstract Described are the synthesis and application of α-t-butyldimethylsilyl-α-methoxyacetaldehyde as a formal methoxyvinyl cation equivalent. Addition of Grignard reagents to the title aldehyde, followed by treatment of the intermediate β-hydroxysilanes with KH, gives good yields of largely Z-methoxyvinylated products. Assuming a Peterson-like elimination mechanism, one can infer that the Grignard addition proceeds with high syn selectivity. These results are consistent with a chelation control model involving coordination to the α-methoxy group in the title aldehyde rather than an alternative stereoelectronic Felkin-Anh-type model. It must be noted that a steric Felkin-Anh model also accounts for the observed stereochemistry. All told, the title reagent can be employed to efficiently append a Z-configured methoxyvinyl group to an appropriate R-M species, in two steps.
Original language | English (US) |
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Article number | 45992 |
Pages (from-to) | 3575-3579 |
Number of pages | 5 |
Journal | Tetrahedron Letters |
Volume | 56 |
Issue number | 23 |
DOIs | |
State | Published - May 25 2015 |
Keywords
- Chelation control
- Methoxyvinylation
- Peterson elimination
- Rieke magnesium
- Steric Felkin-Anh model
- α-Silyl-α-methoxyacetaldehyde
ASJC Scopus subject areas
- Biochemistry
- Drug Discovery
- Organic Chemistry