If we have 1,3-diphenylprop-2-en-1-one, will it give positive Tollens test? I think aldol reactions are reversible under basic conditions. Here there are mildly basic conditions, so will we get back the reactants of the aldol reation?

This question was part of JEE ADVANCED 2016 where they asked which will give Tollens reagent test. I feel it has mildly basic conditions for KOH, hence it should perform reverse aldol and thus this should be the Answer. But the official answer key says no.

Please help me out because I can't understand how to distinguish between the two types.

  • $\begingroup$ Reverse aldol on this sytem will not occur under mild condtions. The extended delocalisation of the system makes it pretty stable. I think you would need forcing condtions to get the reverse aldol $\endgroup$ – Waylander Mar 24 '20 at 11:16
  • $\begingroup$ Ok then we must be using a strong base. oh- will not be sufficient here. But if it had not dehydrated then could we have done the retro aldol using weaker bases like oh-? $\endgroup$ – Alex Mar 24 '20 at 12:03
  • $\begingroup$ Yes, aldol products that still have the alcohol do not have the same level of stability, $\endgroup$ – Waylander Mar 24 '20 at 12:11
  • $\begingroup$ Thanks I got it now. $\endgroup$ – Alex Mar 24 '20 at 16:17

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