How do you add a carbon to an alkene?

Question

I have pentene and I need to add a carbon in order to make a carboxylic acid, but I don't remember the reaction to add a carbon.

yes, i'm in organic 2. the pentene is an n-pentene, sorry i forgot to add that

we just got through the alkylation of methylenes, if that helps at all.

Answer 1

Questions first:
1. Is it n-pentene? (or 2- or 3- pentene?)
2. If it's n-pentene, are you allowed to just OXIDIZE the terminal carbon? (You lose the last C to CO2, but you CAN go from C=C to aldehyde to acid...) Therefore,
3. Must you retain all your carbons? Or does it matter?

Speaking from the perspective of an organic prof, it depends on what chapter you're in. Don't want to slam you with something you haven't or won't have... So how 'bout clueing me in on where you are in Org II?

Will respond.

P.S. Ian I (above) is right but you need to be cautious, and don't reduce the -CN to an amine instead.

Answer 2

1.Oxidative Cleavage of an Alkene Using Hot Alkaline KMnO4 (Fig 5-a)

2.Adding a carbon by cyanide(to lengthen the carbon chain followed by the hydrolysis of the newly formed nitrile.

Answer 3

Use a cyanide. That'll give you a nitrile. Acid hydrolysis will turn that into a carboxylic acid.