Question

1. you have been tasked to create a colourless liquid with an apple odour. outline an efficient method (with names, structural diagrams and reaction types) for the production of pentyl propanoate (a colourless liquid with an apple odour) from a 3 carbon alcohol and an alkene to accomplish this task. show the numbered series/type of reactions necessary. use the flowchart provided and back of the page (most likely necessary).

Explanation:

Step1: Produce propanoic acid from 3 - carbon alcohol (propanol)

Oxidation of propanol (\(CH_3CH_2CH_2OH\)):

$$ CH_3CH_2CH_2OH+O_2\xrightarrow{K_2Cr_2O_7/H^+}CH_3CH_2COOH + H_2O $$

This is an oxidation reaction. The structural formula of propanoic acid is \(CH_3CH_2COOH\).

Step2: Produce pentanol from an alkene (1 - pentene)

1 - pentene (\(CH_2 = CHCH_2CH_2CH_3\)) undergoes hydration reaction:

$$ CH_2=CHCH_2CH_2CH_3 + H_2O\xrightarrow{H^+}CH_3CH(OH)CH_2CH_2CH_3 $$

(Markovnikov addition, major product is 2 - pentanol, but we can also get 1 - pentanol as a minor product or through other isomer - free methods like hydroboration - oxidation. For simplicity, assume we get pentanol \(C_5H_{11}OH\)). The structural formula of pentanol (taking 1 - pentanol as an example) is \(CH_3CH_2CH_2CH_2CH_2OH\))

Step3: Produce pentyl propanoate

Esterification reaction between propanoic acid (\(CH_3CH_2COOH\)) and pentanol (\(C_5H_{11}OH\)):

$$ CH_3CH_2COOH+C_5H_{11}OH\xrightarrow{H^+}CH_3CH_2COOC_5H_{11}+H_2O $$

The structural formula of pentyl propanoate is \(CH_3CH_2COOCH_2CH_2CH_2CH_2CH_3\)

Answer:

First, oxidize propanol (\(CH_3CH_2CH_2OH\)) to propanoic acid (\(CH_3CH_2COOH\)) (oxidation reaction). Then, convert an alkene (e.g., 1 - pentene \(CH_2 = CHCH_2CH_2CH_3\)) to pentanol (\(C_5H_{11}OH\)) (hydration or hydroboration - oxidation reaction). Finally, react propanoic acid and pentanol to form pentyl propanoate (\(CH_3CH_2COOCH_2CH_2CH_2CH_2CH_3\)) (esterification reaction).