[rrr]

Hello!
Help me please to define substance!

Optically active substance Z which has structure C₅H₁₀O, decolours a bromine solution in CCl₄. At restoration on the catalyst it attaches 1 moth of hydrogen and turns to optically active substance Y which has structure C₅H₁₂O. At reaction Y with SOCl₂ forms optically inactive substance X. HNMR and IR for Z:

[discodermolide]

Hello!
Help me please to define substance!

Optically active substance Z which has structure C₅H₁₀O, decolours a bromine solution in CCl₄. At restoration on the catalyst it attaches 1 moth of hydrogen and turns to optically active substance Y which has structure C₅H₁₂O. At reaction Y with SOCl₂ forms optically inactive substance X. HNMR and IR for Z:

Should be obvious from the spectral date, what is the broad IR band centered at 3400CM-1?
What is the NMR signal at 5.5-5.6ppm? And the signal at 4.25 (by the way, what is the multiplicity of this signal?)

[rrr]

I think that the signal in the field of 3500 Sm-1 speaks to us about hydroxyl group
NMR spectrum has been made on the bad emulator with the bad permission that's why it is difficult to discuss about multiplicity of signals.
5.5-5.6 - double doublet
and I have forgotten to tell that solvent CDCl₃

[rrr]

by the way, I have two variants:

[orgopete]

I think you might be able to make a guess between 12 and 13 using the adjacency rules. I understand that if you could see the methyl group splittings, it would make it easy, but there is considerable splitting that you can see in the alkene region. If needed, look up what those patterns look like in authentic compounds in SDBS database.

[cundi]

I think none of them (nor 12, nor 13) are the correct molecule.

My proposal is Pent-2-en-1-ol.

[bolo]

My proposal is Pent-2-en-1-ol.

This can't be an optically active compound. It means rrr is right and I'd guess it's rather an enantiomer of E isomer.

[orgopete]

See http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/img_disp.cgi?disptype=disp3&imgdir=hsp&fname=HSP42010&sdbsno=13594