Posts Tagged ‘lower energy triplet state’

Feist’s acid. Stereochemistry galore.

Thursday, April 4th, 2013

Back in the days (1893) when few compounds were known, new ones could end up being named after the discoverer. Thus Feist is known for the compound bearing his name; the 2,3 carboxylic acid of methylenecyclopropane (1, with Me replaced by CO2H). Compound 1 itself nowadays is used to calibrate chiroptical calculations[cite]10.1021/ct300359s[/cite], which is what brought it to my attention. But about four decades ago, and now largely forgotten, both 1 and the dicarboxylic acid were famous for the following rearrangement that gives a mixture of 2 and 3[cite]10.1021/ja00747a019[/cite]. I thought I might here unpick some of the wonderfully subtle stereochemical analysis that this little molecule became subjected to.