Question

A student is conducting a reaction (not necessarily your Diels-Alder reaction). They are monitoring the progress of their reaction using standard silica TLC with DCM as their eluent. Each of their plates is spotted from left to right with pure starting material, a co-spot, and finally, their reaction mixture alone. Based on the TLC place shown below, you would conclude... that the reaction is complete and they can proceed with isolating their product. that their reaction is working, but needs to react longer before proceeding with product isolation, that their reaction is not working at all and they should start over that something is amiss with their TLC plate and they should run another TLC plate before making any decision about how to proceed. that the starting material and product are unable to be separated and they need to find a different type to TLC plate or a different eluent in order to determine if their reaction is working that some product has been formed but that the yeild is too low to be useful and they should start over

Answer 1

If the sequence of the spotted samples in the TLC plate from left to right is pure starting material, co-spot, and the final reaction mixture respectively, the final reaction mixture cannot be below the co-spot! It should at least travel to the height of co-spot (actually it should travel to the height of starting material giving a blur spot too!). So clearly there is something wrong in the TLC and the option is-

Option 4. that something is amiss with their TLC plate and that they should run another before making any decision about how to proceed.

The following is the TLC plate that should have been obtained to monitor the reaction progress-

A student is conducting a reaction (not necessarily your Diels-Alder reaction). They are monitoring the progress of their reaction using standard silica TLC with DCM as their eluent. Each of their plates is spotted from left to right with pure starting material, a co-spot, and finally, their reaction mixture alone. Based on the TLC place shown below, you would conclude... Ideal TLC plate to monitor progress of reaction Pure Co-spot Reaction Starting Mixture Material