[damac]

Hi all i have a couple things i have to convert 1-bromobutane to

3. 1-butyne

does this look correct?

CH3CH2CH2CH2Br + NaC2CH --> CH3CH2C(triple bond)CH

4. CH3CH2CH2CH2CN
I think that i have found what was wrong with it

CH3CH2CH2Br + NaCN --> CH3CH2CH2CH2CN + NaBr

5. CH3CH2CH2CH2-O-C(=O)CH3

Not sure please help

[akami]

1-Octane
You like heavy chemistry dude! simply make a Wurtz coupling (2 BuBr + Na gives C8H18 + NaBr)
The method you describe is ok for cross coupling

2-Butyne
SN reaction of your BuBr with water and alkali gives you BuOH. Dehydrate the alcohol on strong acid to obtain butene. Brominate your alkene to get 1,2-dibromobutane. React with alkali to obtain corresponding alkyne

3-valeronitrile
Simply react BuBr with alkaline cyanide like cyannure in an alcool

[movies]

Another alternative for 1 would be direct reduction with LiAlD₄ (lithium aluminum deuteride).

For octane (2), that reaction is called the Corey-House.  Should work fine for these purposes.

For 3, you could convert to the alkene directly by an E2 elimination with a very hindered base like sodium t-butoxide.  That would avoid having to make the alcohol.  The rest is as Akami wrote.

For 4, the only thing wrong is that you are missing a carbon in your butyl bromide starting material.  And you need a counterion for cyanide, say potassium.

For 5 I think you could get away with an S_N2 displacement of Br with something like sodium acetate.  Alternatively, you could make the alcohol and then react the alcohol with acetic anhydride or acetyl chloride.  Lots of options.