write equations to show the synthesis pathway for ethyl-3-hydroxybutanoate. An alkane and alcohol of your choice are the starting materials.
To synthesize ethyl-3-hydroxybutanoate, we'll need an alkane and an alcohol as starting materials. Let's choose ethane as the alkane and propanol as the alcohol.
The synthesis pathway can be divided into three steps: oxidation of the alcohol to an aldehyde, aldol condensation reaction, and esterification.
Step 1: Oxidation of propanol to propanal
Propanol can be oxidized to propanal by using an oxidizing agent such as potassium dichromate (K2Cr2O7) and sulfuric acid (H2SO4). The balanced equation is:
CH3CH2CH2OH + [O] → CH3CH2CHO + H2O
Step 2: Aldol condensation reaction
The propanal obtained in the previous step can undergo an aldol condensation reaction with itself to form a β-hydroxyaldehyde. Here, one molecule of propanal acts as the donor of an enolate ion, while another molecule of propanal acts as the acceptor. The reaction is catalyzed by a base such as sodium hydroxide (NaOH). The equation for this reaction is:
CH3CH2CHO + CH3CH2CHO → CH3CH2CH(OH)CH2CHO
Step 3: Esterification
In the final step, the β-hydroxyaldehyde obtained from aldol condensation can be converted into the desired ethyl-3-hydroxybutanoate by esterification. This reaction involves the reaction of the β-hydroxyaldehyde with ethanol (C2H5OH) in the presence of an acid catalyst, such as sulfuric acid (H2SO4). The equation for esterification is as follows:
CH3CH2CH(OH)CH2CHO + C2H5OH → CH3CH2CH(OCH2CH3)COOH + H2O
Overall, the synthesis pathway for ethyl-3-hydroxybutanoate using ethane and propanol as starting materials involves the oxidation of propanol to propanal, followed by an aldol condensation reaction and esterification.