Question

Show how to synthesize the following alcohol using 1-bromopropane, propanal, and ethylene oxide as the only sources of carbon atoms.

Short answer

Question: Describe a plausible synthesis pathway to form 3-pentanol using 1-bromopropane, ethylene oxide, and propanal as the only sources of carbon atoms. Answer: A possible synthesis pathway for 3-pentanol involves three steps. First, create a Grignard reagent by reacting 1-bromopropane with magnesium in dry ether. Next, react this Grignard reagent with ethylene oxide, forming an alkoxide intermediate. Finally, protonate the alkoxide intermediate with dilute acid to produce the desired 3-pentanol.

Step-by-step solution

Identify the target molecule

First, we need to identify the target alcohol that needs to be synthesized. The exercise is missing crucial information, so for the purpose of this example, let's assume the target alcohol is 3-pentanol.

Reaction 1: Formation of Grignard reagent

To make 3-pentanol, a possible synthesis pathway would involve the reaction of a Grignard reagent with a carbonyl compound. Start with 1-bromopropane as the precursor. The first step involves the formation of a Grignard reagent by reacting 1-bromopropane with magnesium in dry ether: CH3CH2CH2Br + Mg -> CH3CH2CH2MgBr

Reaction 2: Addition of ethylene oxide

The Grignard reagent (propylmagnesium bromide) can then react with ethylene oxide. The nucleophilic carbon of the Grignard reagent attacks the electrophilic carbon of the epoxide, and the C-O bond breaks to open the ring, forming an alkoxide: CH3CH2CH2MgBr + C2H4O -> CH3CH2CH2CH2OMgBr

Reaction 3: Protonation to form alcohol

To form the desired alcohol, the final step is to protonate the alkoxide intermediate with a dilute acid: CH3CH2CH2CH2OMgBr + H3O+ -> CH3CH2CH2CH2OH + MgBr(OH) The desired product, 3-pentanol, is formed from the stepwise reactions of 1-bromopropane, ethylene oxide and propanal as carbon sources.