Senyawa Karbon Turunan Alkana • Part 3: Tatanama Eter / Alkoksialkana

Summary

In this video, the channel explains IUPAC and common naming conventions for alkyl ether compounds, focusing on the systematic naming rules and examples. It covers how to identify the main chain, determine the alkyl groups, and assign priority in naming. The video explores both IUPAC and common names for various ethers, such as methyl ethyl ether and diethyl ether, and provides clear examples. Viewers also learn about symmetrical ethers, naming structures, and the proper order of naming different substituents in chemical compounds.

Takeaways

• 😀 IUPAC naming of ethers follows the alkoxy-alkane naming system, where the alkoxy group cannot have more carbon atoms than the alkane chain.
• 😀 Ethers have two naming systems: IUPAC and common names. IUPAC names are based on the alkoxy-alkane structure, while common names are simpler, like alkyl alkyl ether.
• 😀 Symmetrical ethers (where both alkyl groups are the same) have simpler common names, such as diethyl ether.
• 😀 The IUPAC method prioritizes identifying the longest carbon chain as the main alkane, while the alkoxy group is treated as a branch or substituent.
• 😀 When naming ethers with multiple branches, the branches are numbered based on the lowest possible number, starting from the end closest to the functional group.
• 😀 In IUPAC naming, if more than one branch is present, their names are listed alphabetically with prefixes like 'di-', 'tri-', etc. to indicate the number of identical branches.
• 😀 When naming ethers, if two branches have the same number of carbons, the branch with fewer carbon atoms is named as the alkoxy group.
• 😀 Common names for ethers simplify the structure, such as calling a methyl-ethyl ether just 'methyl ethyl ether'. For symmetrical ethers, redundancy is avoided (e.g., 'diethyl ether').
• 😀 IUPAC rules for numbering carbon chains prioritize functional groups, ensuring that they get the lowest possible number in the name.
• 😀 The script includes several examples to illustrate how to apply these naming conventions to various ether structures, providing clarity on how to identify the main chain and branches.

Q & A

What is the IUPAC naming system for ethers?

The IUPAC naming system for ethers involves naming them as alkoxy alkanes. The alkoxy group is named based on the number of carbon atoms it contains, and the alkane part is named based on the longest carbon chain attached to the oxygen atom, ensuring that the number of carbons in the alkoxy group is not greater than the number of carbons in the alkane.

How are common names for ethers derived?

In the common naming system, ethers are named based on the alkyl groups attached to the oxygen atom. These groups are listed alphabetically, and the term 'ether' is added at the end. For symmetric ethers, where the alkyl groups are identical, the prefix 'di-' is used, followed by the alkyl group and 'ether'.

What is the difference between IUPAC and common names for symmetric ethers?

For symmetric ethers, the IUPAC name includes both alkyl groups and 'ether', while the common name simply uses the name of the alkyl group followed by 'ether'. For example, 'dimethyl ether' is used in common naming, while IUPAC would use 'methoxy methane'.

What is the priority when naming ethers in the IUPAC system?

In the IUPAC system, the priority is given to the longest carbon chain attached to the oxygen atom, which becomes the main alkane chain. The shorter alkyl group attached to the oxygen is named as the alkoxy group.

How are branches identified when naming ethers according to IUPAC?

Branches in ethers are identified as alkyl groups. If multiple branches are present, they are named according to the number of carbon atoms in the group, and their positions on the main chain are specified with numbers. In cases where more than one type of branch is present, the branches are listed alphabetically.

How is the numbering of atoms done in the IUPAC system for ethers?

The numbering starts from the end of the main chain closest to the oxygen atom. This ensures that the oxygen atom is at the lowest numbered position. If both ends give the same number, the other branches are numbered based on the position of the alkyl groups.

What happens when there are multiple branches of the same type in the IUPAC naming system?

When there are multiple branches of the same type, the number indicating their position is repeated. For example, '2,3-dimethyl' means that there are two methyl groups at positions 2 and 3 on the main chain.

How are alkyl groups and alkoxy groups treated in terms of priority during naming?

Alkyl groups and alkoxy groups are both treated as branches. However, alkoxy groups have priority when numbering the main chain, meaning the position closest to the oxygen atom is given the lowest possible number.

What is the IUPAC name for an ether with a structure containing a three-carbon chain with a metoxy group at position 2?

The IUPAC name would be '2-methoxypropane' if there is a methoxy group (–OCH3) attached at position 2 of the three-carbon chain (propane).

Can a common name be used for a compound if it is too complex to name with the IUPAC system?

Yes, common names are sometimes used for simpler identification, especially when the compound is widely recognized, such as 'diether' for 'diethyl ether'. However, IUPAC naming is preferred for more precise identification, especially in scientific contexts.