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?
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