All that borane is actually the stuff that reduces the acid to alcohol.
NaBH4 does, so ketones and aldehydes are reduced to secondary and primary alcohols, respectively.
This is what helps us classify the reaction as a reduction.They can be easily synthesized from amino alcohols which are also commercially available but they too cost more then Im willing to pay.That is, the first step in the reaction is coordination of a lone pair from the carbonyl oxygen (a nucleophile) to the aluminum (electrophile).It will also reduce code promo les mots sont des cadeaux 2018 other carbonyl compounds such as amides, aldehydes, ketones, and nitriles.Version.2 just got released, with a host of corrections and a new page index.But the key point is that the carbon-mercury bond is broken, and a new carbon hydrogen bond is formed, and it is NaBH4 which performs this reaction.Here are some examples of it in action.For our purposes, sodium borohydride is really useful for one thing: it will reduce aldehydes and ketones.
Ive been doing it in 200 mmol scale and works just great, giving the amino alcohol in good 70 yield after recrystallization from toluene.
Having just talked about the oxidation ladder, it makes sense to start going into reagents for oxidation and reduction reactions.Thats it for today.In a blatant plug for the.Its most useful for the reduction of esters to aldehydes.This forms the C-H bond, and breaks the C-O bond, resulting in a new lone pair on the oxygen, which makes the oxygen negatively charged (FYI: we call these negatively charged oxygens alkoxides, as they are deprotonated alcohols). .Lately Ive been doing quite a few asymmetric Michael additions using a chiral oxazolidinone, or one of the thio variants, as a chiral auxiliary.