4H-1,3-Dioxins

Chlororaethyl-2,2-dimethyl-1,3-dioxen-4-one 4H-1,3-Dioxin-4-one, 6-(chloroniethyl)-2,2-diraethyl- (11) (81956-31-2)... 

DIETHYLPHOSPHONOHTTHYL-2,2-OIMETHYL-l. 3-DI0XEN-4-0NE (Phosphor)ic acid, [(2, 2-dwethyl-4-OXO-4H-1,3-dioxin-6-yl)nethyl])-, ... 

H-l,2-Oxazin 3-Ethoxycarbonyl-6-methoxy-5-methyl- E9a, 99 (Methylen -+ En —CH3) 2H-l,3-Oxazin 3-Butyl-2,4-dioxo-6-methyl-3,4-dihydro- E15/2, 2418 (4-Oxo — 4H-1,3-dioxin/A + R-NCO)... 

H-1,3-Dioxin 2-tert.-Butyl-5-methyl- E14a/1, 657 (exo -r endo-En)... 

The first total synthesis of the cytotoxic agent (+)-euplotin A was completed by the research team of R.L. Funk. The key step of the synthetic effort was the intramolecular hetero DIels-Alder cycloadditlon of a 3-acyl oxadiene (generated from 5-acyl-4H-1,3-dioxins via thermal retrocycloaddition) with a substituted dihydrofuran to afford the tricyclic skeleton of the natural product. The correct relative stereochemistry of the required dihydrofuran substrate was established using the Paterno-Buchi reaction between ethyl glyoxylate and furan. Subsequently, the oxetane ring was opened stereoselectively under Lewis acid catalysis. 

Aungst, R. A., Jr., Funk, R. L. Synthesis of (Z)-2-Acyl-2-enals via Retrocycloadditions of 5-Acyl-4-alkyl-4H-1,3-dioxins Application in the Total Synthesis of the Cytotoxin ( )-Euplotin A. J. Am. Chem. Soc. 2001,123, 9455-9456. 

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