A classic example for favoring the keto form can be seen in the equilibrium between vinyl alcohol and acetaldehyde ( K = [ enol ] / [ keto ] H " 3 ?10 " 7 ).
12.
Also, when it is irradiated with UVA light, it generates a triplet excited state in the keto form which can either cause the avobenzone to degrade or it can transfer energy to biological targets and cause deleterious effects.
13.
A compound containing a carbonyl group ( C = O ) is normally in rapid equilibrium with an enol tautomer, which contains a pair of doubly bonded carbon atoms adjacent to a hydroxyl ( " OH ) group, C = C-OH . The keto form predominates at equilibrium for most ketones.
