Toluene → HCID 9797046, compound

Participants

Reaction Steps

To a dry toluene solution of the ester 52 (361 mg, 1.0 mmole) under N2 was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (266 mg, 1.13 mmole), bis(trimethylsilyl)trifluoroacetamide (1.07 ml, 4 mmole) and trifluoromethanesulfonic acid (7 ml, 0.077 mmole) and the clear red solution stirred at room temperature for 24 hours. Methylacetoacetate (11 ml, 0.1 mmole) was added and after stirring for 1 hour at room temperature the solution was refluxed for 24 hours. The reaction mix was concentrated in vacuo to a small volume and the residue dissolved in methylene chloride and extracted with an aqueous solution of 1.5% sodium carbonate plus 0.5% sodium sulfite, 5% sodium bicarbonate, dried over magnesium sulfate and concentrated in vacuo to give 328 mg crude product. Purificaton by flash chromatography on silica gel in 9:1 methylene chloride:acetone gave 229 mg of the unsaturated ester 69.

Provenance & Evidence