An oxepinone route to carbohydrate based oxepines

Castro, Steve; Johnson, Cynthia D.; Surana, Bikash; Peczuh, Mark W.

doi:10.1016/j.tet.2009.07.041

Cited by 16 publications

(10 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We assigned the identity of the 7 -endo-dig products on the basis of the 1 H NMR chemical shifts of the vinylic protons (Figure 3 ). For compounds 8 , we observed a chemical shift for the vinyl proton at 5.3 ppm for aliphatic R 2 groups and at 5.8–5.9 ppm for aromatic R 2 groups, which is in accordance with shifts reported in the literature for similar compounds like 6,7-dihydrooxepin-4(5 H )-ones (5.3–5.8 ppm), 54 , 55 5-substituted furanones (5.3 ppm), 56 and 2-substituted dihydropyranones (5.3 ppm). 56 − 58 This also ruled out the possibility that 6 -exo-trig products had formed, in which case the 1 H NMR chemical shifts for the vinyl protons would be expected at 6.7 ppm.…”

Section: Resultssupporting

confidence: 90%

Enantioselective Synthesis of 3,4-Dihydro-1,2-oxazepin-5(2H)-ones and 2,3-Dihydropyridin-4(1H)-ones from β-Substituted β-Hydroxyaminoaldehydes

Ranade

Georg

2014

J. Org. Chem.

View full text Add to dashboard Cite

The synthesis of 3,4-dihydro-1,2-oxazepin-5(2H)-ones and 2,3-dihydropyridin-4(1H)-ones from β-substituted β-hydroxyaminoaldehydes is reported. The β-hydroxyaminoaldehydes were prepared by enantioselective organocatalytic 1,4-addition of N-tert-butyl (tert-butyldimethylsilyl)oxycarbamate to α,β-unsaturated aldehydes (MacMillan protocol). Alkyne addition to the aldehydes followed by alcohol oxidation furnished N-Boc O-TBS-protected β-aminoynones. Removal of the TBS protecting group initiated a 7-endo-dig cyclization to yield previously unknown 3,4-dihydro-1,2-oxazepin-5(2H)-ones. Reductive cleavage of the N–O bond of the oxazepinones and Boc-deprotection provided 2-substituted 2,3-dihydropyridin-4(1H)-ones via 6-endo-trig cyclization. 2,3-Dihydropyridin-4(1H)-ones are versatile intermediates that have been used for the synthesis of many alkaloids. The new protocol allows the synthesis of 3-dihydropyridin-4(1H)-ones carrying an array of substituents at C2 that cannot be prepared from commercial β-amino acids or by one-carbon homologation of proteinogenic amino acids. The use of readily available β-hydroxylaminoaldehydes expands the utility of our previously reported method to prepare 2,3-dihydropyridin-4(1H)-ones from β-amino acids as the source of diversity and chirality. A broad substrate scope is possible because β-aminoaldehydes can be prepared from α,β-unsaturated aldehydes by an enantioselective organocatalytic process.

show abstract

Section: Resultssupporting

confidence: 90%

Enantioselective Synthesis of 3,4-Dihydro-1,2-oxazepin-5(2H)-ones and 2,3-Dihydropyridin-4(1H)-ones from β-Substituted β-Hydroxyaminoaldehydes

Ranade

Georg

2014

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…After CsF mediated desilylation, the desired alkynyl ketose 8, isolated as a mixture of α/β lactols and the corresponding ketone was obtained (Scheme 2). 24 The anomeric cyano group was then diastereoselectively introduced under classic conditions, 12 to afford 6 as a single diastereoisomer, but with a moderate 20% yield (Scheme 2a). Several reaction conditions (Lewis acid/solvent/ temperature) were then investigated and after careful optimization, it was observed that a fine control of the temperature was essential to effectively introduce the cyano group.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of novel C-nucleoside analogues bearing an anomeric cyano and a 1,2,3-triazole nucleobase as potential antiviral agents

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Aldehyde 56 available from alcohol 55 was converted into the corresponding C-alkynyl glycoside 57 in moderate yield by using standard CoreyFuchs protocol [24] followed by cross-enyne metathesis with ethylene by using Grubbs second-generation catalyst 54 to afford the diene 45 in good yield. The diene 45 was treated individually with quinones 40,41,42,and DMAD (43) followed by oxidative aromatisation to afford the respective Caryl glycosides in good yield (Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…The aldehyde 58 was treated with CBr 4 and PPh 3 followed by treatment with nBuLi to afford alkyne 60 in good yield. The alkyne 60 upon sequential enyne metathesis followed by Diels-Alder reactions (40)(41)(42)(43) and aromatisation gave the third set of C-aryl glycosides in good yield (Table 1).…”

Section: Resultsmentioning

confidence: 99%

Application of an Enyne Metathesis/Diels–Alder Cycloaddition Sequence: A New Versatile Approach to the Syntheses of C‐Aryl Glycosides and Spiro‐C‐Aryl Glycosides

Subrahmanyam

Palanichamy

Kaliappan

2010

Chemistry A European J

View full text Add to dashboard Cite

An efficient approach for the synthesis of a variety of C-aryl and spiro-C-aryl glycosides is described. This diversity-oriented strategy employed here relies on a sequential enyne metathesis to generate the 1,3-diene moiety and Diels-Alder reaction with different dienophiles followed by aromatisation. Whereas cross-enyne metathesis with ethylene gas is used to install the 1,3-diene moiety at the anomeric centre for the synthesis of C-aryl glycosides, an intramolecular enyne metathesis on the sugar enyne is performed to generate the 1,3-diene moiety for the synthesis of spiro-C-aryl glycosides. Efforts to extend this strategy to the synthesis of the core structure of natural C-aryl glycoside gilvocarcin are also described. A combination of both C-aryl and spiro-C-aryl glycosides in the same moiety to combine the features thereof has also been accomplished. A tandem enyne metathesis/Diels-Alder reaction/aromatisation has also been attempted to directly access the C-aryl glycosides in one pot albeit in low yield.

show abstract

An oxepinone route to carbohydrate based oxepines

Cited by 16 publications

References 19 publications

Enantioselective Synthesis of 3,4-Dihydro-1,2-oxazepin-5(2H)-ones and 2,3-Dihydropyridin-4(1H)-ones from β-Substituted β-Hydroxyaminoaldehydes

Enantioselective Synthesis of 3,4-Dihydro-1,2-oxazepin-5(2H)-ones and 2,3-Dihydropyridin-4(1H)-ones from β-Substituted β-Hydroxyaminoaldehydes

Synthesis of novel C-nucleoside analogues bearing an anomeric cyano and a 1,2,3-triazole nucleobase as potential antiviral agents

Application of an Enyne Metathesis/Diels–Alder Cycloaddition Sequence: A New Versatile Approach to the Syntheses of C‐Aryl Glycosides and Spiro‐C‐Aryl Glycosides

Contact Info

Product

Resources

About