structures of C5H8O, that gives a positive tollen's test?

Question

Structures of C5H8O, that give a positive Tollen’s test and does not react with bromine?

Answer 1

Ignore the answer given above by the 'Great Thinker'. Ketones will not give a positive Tollen's test. The reaction only occurs in the presence of an aldehyde. During the reaction, the aldehyde is oxidized to the corresponding carboxylic acid, while the silver is reduced from the +1 oxidation state in the formed diamine complex to become elemental silver (no charge). It is likely that your compound is cyclopropylcarboxaldehyde. This would result in an unsaturation of 2, and have no C=C bonds with which Br2 would react.

Finishing up my doctoral research for my PhD, so you can trust the answer.

Answer 2

If you would make the structure of this an acyclic one, you will either get a ketone or an aldehyde with an unsaturated hydrocarbon. This will give a positive test to both Tollen's test (positive for ketone and aldehydes) and Bromine test for unsaturation (since there will be an unsaturated hydrocarbon).

The structure that has C5H8O that will be positive on Tollen's test (meaning, an aldehyde or ketone) but negative on Bromine test (meaning, saturated hydrocarbon) will be a cyclic ketone. Specifically, a CYCLOPENTANONE for that molecular formula.

I can't draw cyclic compds here but just draw a cyclic compound with 5 carbons and one of the carbons is a carbonyl carbon (C=O)

Answer 3

Yes definetly this will give tollen's silver mirror test because the compound is butanal an aldehyde

Answer 4

cyclopentanone