Nature of the transition state for the decarboxylation of .beta.-keto acids

β‐Hydroxycarboxylic Acids from Simple Ketones by Carboxylation and Asymmetric Hydrogenation

“…The decarboxylation is reported to occur from the keto tautomer [22] and, as observed by Rosen-A C H T U N G T R E N N U N G feld, [23] the keto/enol ratio is higher in more polar solvents. At a concentration of 0.08 M at 25 8C, we find that decarboxylation of 2a is faster in solvents that favour a larger keto:enol ratio (Table 3).…”

Uncatalyzed and Amine Catalyzed Decarboxylation of Acetoacetic Acid: An Examination in Terms of No Barrier Theory

“…There remains some uncertainty about details of the mechanism, and in particular about whether the proton transfer is concerted with the C-C bond breaking (3,10,12,13). Amine catalysis has been known for a long time (5,14,15,11,10,16), but is less understood in detail because of the multistep nature of the catalysis.…”

2-Carboxy- and 2,7-Dicarboxy-4,5-benzotropone: Hydrogen-Bonding Patterns of a β-Keto Acid and a Related β-Keto 1,5-Diacid

“…The geometry of jS-keto acids appears attractive for internal hydrogen bonding (Toffoli, Khodadad & Rodier, 1988), consistent with the six-centered internal Hatom transfer underlying their thermal decarboxylation (Logue, Pollack & Vitullo, 1975). However, crystallographically, this hydrogen-bonding mode has been found only in 7-keto acids (and one e-keto acid), requiring larger hydrogen-bonding rings.…”