How would you convert an aldehyde to a ketone?

1 Answer
Nov 27, 2015

You have to add another carbon residue. A Grignard reaction followed by workup and oxidation would give a ketone.


#i. R-C(=O)H + R'-MgBr rarr RC(-OMgBr)R'#
#ii. R-CH(OMgBr)R' + H_2O rarr R-CH(OH)R' + MgBrOH#
#iii. R-CH(OH)R' + [O] rarr RC(=O)R'#

The electrophilic aldehyde will react with a Grignard or lithium reagent to give a new #C-C# bond and (after workup) a secondary alcohol. The secondary alcohol can be easily oxidized by various means to give a ketone.