Is it possible that a reaction of an alpha-chlorocarboxylic acid with an aldehyde work for the Darzens reaction to produce an epoxide (with NaOH as the base, and H3O+ workup)?

  • $\begingroup$ Welcome to ChemSE! What are your thoughts? $\endgroup$
    – user55119
    Commented Aug 16, 2022 at 22:27
  • $\begingroup$ Hi, I've seen many examples of aldehyde reacting with esters in this reaction, but none so far of an aldehyde with a carboxylic acid. The mechanism I have written seems to work on paper, but I am a little unsure about it. Also, I am not sure whether NaOH would be a strong enough base. Any help would be much appreciated. Thanks $\endgroup$
    – Holly
    Commented Aug 16, 2022 at 22:52
  • 5
    $\begingroup$ Any base you would use would form the carboxylate which would risk intra- or intermolecular displacement of chloride. Secondly, to form the dianion you need a much stronger base in an aprotic medium. If step one is feasible, 2 equivalents of lithium diisopropylamine (LDA) in tetrahydrofuran (THF) might do the trick at low temperarure. Then add the aldehyde and warm to room temperature. $\endgroup$
    – user55119
    Commented Aug 16, 2022 at 23:04


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