[prncess23]

hello.

Please help me with this question.

Give the products of the reaction of methylmagnesium chloride (Grignard reagent) with:
a.   acetaldehyde
b.   acetone
c.   ethyl acetate (1 equivalent per Grignard)
d.   ethanol
e.   propylene oxide

[sjb]

How do Grignards react? As, for instance, nucleophiles or electrophiles?

[prncess23]

nucleophiles.

[Dolphinsiu]

You should know what the purpose of Grignard reagent is. Like oxidation, reduction, addition, elimination or substitution.

[AWK]

http://en.wikipedia.org/wiki/Grignard_reagent

[ufalynn88]

you should know that grignard reagents are most definately nucleophilic. the carbon which interacts with Mg is essentially negatively charged. that said, though it is a nucleophile, it will preferentially remove a proton to return to neutrality if it can. so watch out for anything protic.

a. is acetaldehyde nucleophilic or electrophilic? what part of the molecule possesses that character? that will tell you the site of reaction
b. similar to a
c. ethyl acetate-think of functional groups. what makes a good leaving group? is there one here?
d. previously mentioned...
e. are epoxides nucleophilic or electrophilic? if carbon is a negatively charged nucleophile (think sn2) would it attack a more or less hindered position?

[prncess23]

wait...for d...isnt the answer ethanol + methane?

why won't that work?

[Squirmy]

wait...for d...isnt the answer ethanol + methane?

methane is right....the ethanol does not go unchanged.

[prncess23]

so its just methane then? i was told this reaction can't occur...but why?

[sjb]

Methane is only one of your products, there is something else in the pot.

[James Newby]

Be careful with your answer to part c as well.  The product formed after grignard reaction is more reactive than your starting material so would react again with the grignard.