9
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enter image description here The closest reaction I can find is Lossen rearrangement but in that hydroxyamic acid is first converted to its derivative but how will that be possible here?

enter image description here

Moreover, even if I make an amine in this step I cannot proceed further, how will the amine and alcohol react in the next step? Any hints would be appreciated.

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  • $\begingroup$ May I know the source of your reaction? $\endgroup$ – William R. Ebenezer May 9 '19 at 20:40
  • $\begingroup$ This is a problem from my chemistry book. $\endgroup$ – FullBridge May 9 '19 at 20:46
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    $\begingroup$ First deprotonate and then lose carboxylate. The remaining neutral species reranges to an isocyanate. In methanol the isocyanate forms the methyl ester of a carbamic acid. Compare the similarity of the Lossen and Hofmann rearrangements $\endgroup$ – user55119 May 9 '19 at 21:16
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    $\begingroup$ My thoughts. I think you have to deprotonate the NH of the hydroxamic acid and lose OH- to give the isocyanate analogous to the mechanism of the Lossen that you have drawn. This is the only option that makes any kind of sense, and it is known that deprotonation of hydroxamic acids proceeds at NH rather than OH. $\endgroup$ – Waylander May 10 '19 at 18:04
  • $\begingroup$ @Waylander I think that is a possible mechanism as to how it would react also. The N-O bond is likely weak and would not cleave with much difficulty. $\endgroup$ – Tan Yong Boon May 15 '19 at 23:11

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