Has anyone analyzed the products of the reaction of any simple alkyne (eg.: acetylene) with bromine water? Most online references state that a dihalo-addition or tetrahalo-addition happens, but the only experimentally-based reports I found are more than 90 years old and state that dihalooxy-addition happens (although with hypobromous acid), leading to α,α-dibromoaldehydes and α,α-dibromocarboxylic acids (I expect α,α-dibromoketones possible with internal alkynes). Any new data on that?
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2Well, why would they do more research on that? – Mithoron Jul 18 '22 at 14:37
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2Please reference those experimental reports – Ritil Jul 18 '22 at 20:50
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1Internal alkynes afford $\alpha$, $\alpha$-dibromoketones with tribromocyanuric acid in acetic acid. DOI: 10.2174/1570178615666180803152951 – user55119 Jul 18 '22 at 21:58
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There are 4 kinds of reactions which occur for sure:
- addition of dihalogen to alkene and alkyne in carbon tetrachloride gives vicinal dihalide(alkane and alkene respectively).
- addition of hydrohalic acid to alkene and alkyne gives monohalogenated alkane and alkene respectively.
- addition of dilute hydrobromic acid to alkene gives alpha-bromo alkanol
- addition of hydrohalous acid to alkene also gives the same product
If such kind of reactions are possible then I think that the reaction about you are talking should also be possible via tautomerism of alkenol, but I can't see how can carboxylic acids form.
Addition of HOBr across C=C I think this could be helpful
