[rjt027]

Can someone help me with my understanding here?

What is the chain of events when you react a aldehyde with:
   1. NaCN, H₂O
   2. H₃O⁺, Δ

I think the process would go ?
1. NaCN breaks the double bond with Oxygen resulting in
the attachment of -CN to the C bearing the Oxygen as well as attaching an -H to the Oxygen
2. The H₂O, H₃O⁺, Δ cause the replacement of the -CN with a CO₂H

Is this rationale correct?

Thanks in advance guys
-rob

[discodermolide]

The reaction of an aldehyde with a cyanide produces a cyanohydrin, so you first suggestion is ok.
Treatment with acid and heat can possibly do three things:
1 eliminate water to give the unsaturated nitrile
2 eliminate water and hydrolyse the nitrile to give the unsaturated acid
3 hydrolyse the nitrile of the cyanohydrin to give the hydroxy acid.