Equilibration in bicyclic pyroglutamates by ring opening-reclosure

Moloney, Mark G.; Yaqoob, Muhammad

doi:10.1016/j.tetlet.2008.08.021

Cited by 12 publications

(12 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, hydrolysis of alkene 20 proved to be more challenging and purification by flash column chromatography was unsuccessful. This could be explained by a combination of factors, including its high polarity, metal chelation and a possible retro‐aldol reaction . Indeed, purification of protected alcohol 23 , prepared by direct acetylation of the crude 22 , was successful.…”

Section: Resultsmentioning

confidence: 99%

“…This could be explained by a combination of factors, including its high polarity, metal chelation and a possible retro-aldol reaction. [22] Indeed, purification of protected alcohol 23, prepared by direct acetylation of the crude 22, was successful. Acylated analogues 11a and 14a-c were hydrolysed with an excess of LiOH, and reflux of the crude acids in MeCN gave the decarboxylated products 24 and 25a-c as single diastereomers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chemoselective Formation and Reaction of Densely Functionalised Bicyclic Tetramic Acids and Their Biological Activity

et al. 2017

Self Cite

View full text Add to dashboard Cite

Weinreb amide derivatives of tetramates may be effectively accessed by chemoselective Dieckmann reaction, and further react with Grignards in a fully chemoselective reaction, giving rise to unsaturated acyl derivatives not easily available by other routes. These systems are strong chelators of calcium, and some show potent activity against Gram positive bacteria, and one is a first‐in‐class proteasome inhibitor.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Chemoselective Formation and Reaction of Densely Functionalised Bicyclic Tetramic Acids and Their Biological Activity

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…This was due to epimerisation of 32a during basic hydrolysis, probably via a retro-aldol reaction, a phenomenon in these systems which we had reported earlier. 11 Instead, when hydrolysing 32a and treating the crude acid with HATU/DIPEA, spiro-β-lactone 36 was successfully isolated in 21% yield.…”

Section: Preparation Of Fused-and Spiro-β-lactones With a Pyrrolidinomentioning

confidence: 99%

Synthesis and bioactivity of fused- and spiro-β-lactone-lactam systems

et al. 2017

Self Cite

View full text Add to dashboard Cite

An investigation of the formation of fused- and spiro-β-lactone annulate to γ-lactams has shown that the fused systems are formed preferentially, under standard conditions, but that spiro systems are accessible only when the formation of the fused system is blocked and require careful optimisation of reaction conditions. These systems display both weak antibacterial activity and proteasome inhibition.

show abstract

“…8,9 Related aldol ring closures have been reported 10 and it has been suggested that such processes are biomimetic. 11 Of interest to us was the possibility that a similar ring closure might also be applicable to cysteine-derived systems, even though these aldol reactions may be reversible 12 and the five-membered ring containing the large sulfur atom might be expected to influence the outcome of such a reaction. Moreover, of interest was whether the reaction might be extended to thiazolidines other than those derived from pivaldehyde, since such systems exhibited unexpected behaviour in related Dieckmann cyclisations.…”

mentioning

confidence: 99%