What are organic compound positive resulting in Baeyer's test but negative to bromine's essay?

Answer 1

Lancenigo di Villorba (TV), Italy

I had answered yet to a very similar question, near teen days ago.

Nonetheless, I forget an important possibilities.
They exist an entire class of organic compounds which show a positive results to "von Baeyer's test" but a negative result for "bromine water's essay". These compounds are the followings : the "alpha-hydrogen-less aldehydes".
The most common substance belonging to overwritten class are methanale (e.g. formaldehyde) and benzaldehyde.
Aldehydes are known for their reducing reactivity, so they REACT with permanganate's neutral solutions giving off a decoloration of pinkish hue and forming a browing understanding bottom-body(von Baeyer's test) ; the bottom-body is manganese dioxide, as pyrolusite.
Aldehydes COULD REACT also with bromine's water, in effect they undergo to substitution reactions which replace alpha-hydrogen present in aldehydes with bromine atoms ; besides this substitution phenomenon, you see decoloration of orange liquid and gas-flow who flows up (e.g. hydrobromic acid gas, HBr). Many aldehydes REACT NOT with bromine's water, when and if they HAVE NOT alpha-hydrogen in aldehyde's molecules.

CONCLUSIONS
Thus, besides other lab's chemicals (e.g. hydrochloric acid's aqueous solutions or alcoholic lab's stuffs) "alpha-hydrogen-less aldehydes" constitue the main answer. Owing increasing lab's experience, you can proove that hydrochloric acid's solutions and alcoholic stuffs may decolorate permanganate's neutral solutions without show reactions with bromine's water.

Answer 2

Unsaturated.