# Is an aldehyde polar? What occurs when it reacts with methyl magnesium chloride?

Apr 18, 2016

The carbonyl bond is polar in that there is charge separation.

#### Explanation:

Oxygen is more electronegative than carbon, and polarizes electron density towards itself. A representation of the carbonyl bond as $- {\text{^(delta+)C=O}}^{\delta -}$ is reasonable, and this certainly accounts for the reactivity in say a Grignard reaction, i.e:

R^(-)""^(+)MgX + R'C(=O)H rarr R'RC(-O^-)(MgX)^+, in which a carbanionic reagent reacts with the carbonyl to effect $C - C$ bond formation.

Apr 18, 2016

Oxygen is more electronegative than carbon, and polarizes electron density towards itself. A representation of the carbonyl bond as $- {\text{^(delta+)C=O}}^{\delta -}$ is reasonable, and this certainly accounts for the reactivity in say a Grignard reaction, i.e:
R^(-)""^(+)MgX + R'C(=O)H rarr R'RC(-O^-)(MgX)^+, in which a carbanionic reagent reacts with the carbonyl to effect $C - C$ bond formation.