what is the best synthesis of 4-heptanol (CH3CH2CH2)2CHOH

CH3CH2CH2MgBr (2 moles)+formaldehyde (CH2=O) in diethyl ether followed by H3O+

(CH3CH2CH2)2ChMgBr+formaldehyde (CH2=O) in diethyl ether followed by H3O+

CH3CH2CH2MgBr+butanal (CH3CH2CH2CH=O) in diethyl ether followed byH3O+

CH3CH2CH2CH2MgBr+acetone[(CH3)2C=O] in diethyl ether followed by H3O+

1 answer

Aren't these Grignard reactions?
http://www.organic-chemistry.org/namedreactions/grignard-reaction.shtm