Acetylations of strongly basic and nucleophilic enolate anions with N-methoxy-N-methylacetamide

Oster, Timothy A.; Harris, Thomas M.

doi:10.1016/s0040-4039(00)81788-8

Cited by 35 publications

(9 citation statements)

References 11 publications

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“…This fact is compatible with the result that there was no condensation of the lithium enolate of acetophenone with Nmethoxy-N-methylacetamide even when the mixture was refluxed in THF, whereas the condensation of the lithium dienolate of 1-phenyl-1,3-butanedione with N-methoxy-Nmethylacetamide proceeded smoothly at room temperature. 15 Thus, the condensation of the lithium dianion of 2 with 3 proceeded well by the electron-donating participation of the 2-lithiumoxy group in 2, producing 4 in 73-90% yields. The 1 H NMR analysis of 4 shows that all of products exist as enols or enol-keto tautomeric mixtures.…”

Section: Methodsmentioning

confidence: 92%

An Efficient Synthesis of Flavones from 2-Hydroxybenzoic Acids

Lee

Son²,

Park³

2004

Bulletin of the Korean Chemical Society

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Section: Methodsmentioning

confidence: 92%

An Efficient Synthesis of Flavones from 2-Hydroxybenzoic Acids

Lee

Son²,

Park³

2004

Bulletin of the Korean Chemical Society

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“…Air- and moisture-sensitive materials were manipulated under argon with standard glovebox, vacuum line, and syringe techniques. Substrates are all known and prepared using standard literature procedures …”

Section: Methodsmentioning

confidence: 99%

Lithium Enolates Derived from Weinreb Amides: Insights into Five-Membered Chelate Rings

Houghton

Collum

2016

J. Org. Chem.

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Enolization of O-methyl hydroxamic acids (Weinreb amides) in tetrahydrofuran solution with lithium diisopropylamide affords predominantly tetrameric enolates. Aryl substituents on the enolates promote deaggregation. The aggregation states are assigned by using the method of continuous variation in conjunction with 6Li NMR spectroscopy. Decoalescence of the tetramer resonance below −100 °C shows considerable spectral complexity attributed to isomerism of the methoxy-based chelates. Density functional theory calculations were used to examine the consequences of the bite angle of five-membered chelates in cubic tetramers and resulting solvation numbers that were higher than anticipated.

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“…Harris once obtained a similar result, in which the lithium salt of acetophenone with N-methoxy-N-methylacetamide failed to give anything other than the starting materials. 9 Thus, we adopted a Claisen condensation strategy in order to produce 4 in our retrosynthesis. We hypothesized that the condensation between the enolate anion of 10 with lactone 12 could afford 4 (Scheme 4).…”

Section: Introductionmentioning

confidence: 99%