[sissigoon]

In D-A reaction, is endo product or exo product kineticly favored?

[movies]

It will depend, to some degree, on the particular Diels–Alder reaction you are looking at.

What do you think?  Can you propose an experiment that would tell you whether you have the kinetic or thermodynamic product?

[sissigoon]

It will depend, to some degree, on the particular Diels–Alder reaction you are looking at.

What do you think?  Can you propose an experiment that would tell you whether you have the kinetic or thermodynamic product?

If that depends on the experiment, how can we define the exact definition for endo and exo?
I thought endo TS was defined that the electron could delocalize when forming a new ring so that it could stablize the TS and then was kinetically favored.

[movies]

Endo and exo are actually defined for the specific products you get, not for the transition state.  The endo TS is called that because it gives the endo product.

So you seem to know that the endo product is usually the kinetic product, which is true.  Usually the exo product is the thermodynamic product, however.