Provide methods for preparing the following compounds by the Grignard method:

A) 3-pentanol
B) Hexanoic acid

There are also 2 more, but I don't even know how to name them.

C) CH3CH2CCH3OHCH2CH3
D) A cycloalkene (3 double bonds-alternated) with CHOHCH2CH3 attached to it

Please help... I am really lost in this class.

5 answers

There is more than one use of the Grignard reaction to prepare each of these. In practice you would consider cost of starting materials and ease of separation of the product(s) from starting materials.

I assume we are going to use the original Mg based version rather than any of the variations.

A)

CH3CH2Br + Mg -> CH3CH2MgBr

CH3CH3MgBr+CH3CH3CHO ->CH3CH2CH(OH)CH2CH3

B) CH3CH2CH2CH2CH2Br + Mg -> CH3CH2CH2CH2CH2MgBr

CH3CH2CH2CH2CH2MgBr + CO2 -> CH3CH2CH2CH2CH2CH2H

C)CH3CH2C(CH3)(OH)CH2CH3
2-hydroxy-2-methylpentane

CH3Br + Mg -> CH3MgBr

CH3MgBR + CH3CH2C(=O)CH2CH3 -> CH3CH2C(CH3)(OH)CH2CH3

D)Ph=benzene ring
PhCHOHCH2CH3

PhBr + Mg ->PhMgBr

PhMgBr + CH3CH2CHO -> PhCH(OH)CH2CH3

There are alternative answers to each of these, for example for D)

PhCHO (benzaldehyde) + CH3CH2MgBr -> PhCH(OH)CH2CH3
oops just spotted a typo in B)

the last line should be

CH3CH2CH2CH2CH2MgBr + CO2 -> CH3CH2CH2CH2CH2CO2H

You might like to have a closer look at D) and decide which of the two methods might be preferred and why. Things to consider are the possible by-products and unused starting materials.
Thank you so much. However, I thought B) hexanoic acid had to have a C=OOH?
Oops, I didn't get the correction note before I submitted, but thanks I appreciate your help.
CH3CH2C(=O)CH2CH3