Ethers are class of organic compounds that contain ether group – an oxygen atom connected to two alkyl groups or aryl groups. They have the general formula R – O – R′, where R and R′ represents the alkyl or aryl groups. Ether, like water have a tetrahedral geometry i.e., oxygen is sp3 hybridised. The C – O – C bond angle in ethers is slightly greater than the tetrahedral angle due to repulsive interactions between the two bulky groups when they are attached to oxygen.
The IUPAC name of the ether
CH2 = CH — CH2 — O — CH3 is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 3-Methoxyprop-1-ene
In the IUPAC name of an ether, the larger hydrocarbon part is the parent and the smaller –OR group is named as an alkoxy substituent. The parent chain is numbered so that the C=C double bond gets the lowest locant.
In \( \ce{CH2=CH-CH2-O-CH3} \) the parent is the three-carbon chain with the double bond (propene), and –\( \ce{OCH3} \) is methoxy:
\( \overset{1}{\ce{CH2}}{=}\overset{2}{\ce{CH}}{-}\overset{3}{\ce{CH2}}{-}\ce{O-CH3} \)
The double bond starts at C-1 and the methoxy group is on C-3, so the name is 3-methoxyprop-1-ene (common name: allyl methyl ether).