Question

Show how to perform the following synthetic transformations using any reagents necessary.

A. 1-hexyne to hexanal, CH3CH2CH2CH2CH2CHO O || ( Its post to be double oxygen on the bolded carbon)
B. 1-hexyne to 2-hexanone (CH3CCH2CH2CH2CH3)
C. 3-heptyne to trans-3-heptene
D. 4-octyne to butanoic acid (CH3CH2CH2COOH)
E. propyne to 2-hexyne

Answer 1

To transform 1-hexyne to hexanal, hydrogenation with Pd/C can be used to convert 1-hexyne to 1-hexene, which can then be oxidatively cleaved to hexanal. The synthesis of 2-hexanone from 1-hexyne involves converting 1-hexyne to 2-hexyne using chlorine, and then oxidatively cleaving 2-hexyne to 2-hexanone. For the transformation of 3-heptane to trans-3-heptene, selective hydrogenation with Lindlar's catalyst is used. 4-octyne can be converted to butanoic acid through partial oxidation to 4-octenal, followed by oxidation to butanoic acid. Lastly, the transformation of propyne to 2-hexyne involves brominating propyne to form 1,2-dibromopropane, converting it to 2-bromopentane, and then deprotonating it with a strong base to yield 2-hexyne.

Step-by-step explanation:

To perform the synthetic transformation from 1-hexyne to hexanal, the following steps can be taken:

1. Convert 1-hexyne to 1-hexene by hydrogenation using a suitable catalyst, such as palladium on carbon (Pd/C).
2. Convert 1-hexene to hexanal by oxidative cleavage using a reagent like ozone (O3) followed by reduction with zinc (Zn) and acetic acid (CH3COOH).

The synthetic transformation from 1-hexyne to 2-hexanone can be achieved by:

1. Convert 1-hexyne to 2-hexyne by adding one equivalent of chlorine (Cl2) across the triple bond.
2. Convert 2-hexyne to 2-hexanone by oxidative cleavage using a reagent like ozone (O3) followed by treatment with water (H2O) and a base, such as sodium hydroxide (NaOH).

The synthetic transformation from 3-heptyne to trans-3-heptene can be accomplished by:

1. Convert 3-heptyne to 3-heptene by selective hydrogenation of the triple bond using a suitable catalyst, such as Lindlar's catalyst (Pd/CaCO3 or Pd/BaSO4).
2. The converted 3-heptene is already in transform.

The synthetic transformation from 4-octyne to butanoic acid can be done by:

1. Convert 4-octyne to 4-octenal by partial oxidation using a reagent, such as potassium permanganate (KMnO4) or ozone (O3).
2. Convert 4-octenal to butanoic acid by oxidation using a strong oxidizing agent, such as potassium permanganate (KMnO4) or chromic acid (H2CrO4).

The synthetic transformation from propyne to 2-hexyne can be achieved by:

1. Convert propyne to 1,2-dibromopropane by adding two equivalents of bromine (Br2) across the triple bond.
2. Convert 1,2-dibromopropane to 2-bromopentane by reacting with sodium iodide (NaI) in acetone (CH3COCH3).
3. Convert 2-bromopentane to 2-hexyne by treating with a strong base, such as sodium amide (NaNH2) in liquid ammonia (NH3).

Answer 2

To perform the synthetic transformations, you will need different reagents for each reaction. Here are the steps for each transformation:

Step-by-step explanation:

To perform the synthetic transformations, you will need different reagents for each reaction. Here are the steps for each transformation:

A. 1-hexyne to hexanal: React 1-hexyne with ozone (O3) to create an ozonide intermediate. Treat the ozonide with zinc (Zn) in acetic acid (CH3COOH) to form a Criegee intermediate. Finally, the Criegee intermediate rearranges to form hexanal.

B. 1-hexyne to 2-hexanone: Start by reacting 1-hexyne with a strong oxidizing agent like KMnO4 or H2CrO4 to break the triple bond and form a carboxylic acid. Then, reduce the carboxylic acid using a reducing agent like LiAlH4 to obtain 2-hexanone.

C. 3-heptyne to trans-3-heptene: To convert 3-heptyne to trans-3-heptene, you will need to perform a partial reduction using Lindlar's catalyst (Pd/CaCO3) in the presence of quinoline (C9H7N). This catalyst selectively reduces the triple bond to create the cis-3-heptene, which can then be converted to trans-3-heptene using a strong base like NaOH.

D. 4-octyne to butanoic acid: Start by reacting 4-octyne with H2 in the presence of Lindlar's catalyst to obtain cis-4-octene. Then, perform hydroxylation on the double bond of cis-4-octene using a strong oxidizing agent like KMnO4 to obtain cis-4-octanol. Finally, oxidize cis-4-octanol using an oxidizing agent like PCC or CrO3 to achieve the desired product, butanoic acid.

E. Propyne to 2-hexyne: React propyne with excess HCl in the presence of a catalyst like AlCl3 to form propyl chloride. Then, perform an E2 elimination reaction on propyl chloride using a strong base like NaOH to obtain 2-hexyne.