Draw the structures and give the common and systematic names...

Key Concepts

IUPAC and Common Nomenclature

Nomenclature in organic chemistry includes both systematic (IUPAC) and common naming systems. IUPAC names are based on a set of rules that specify the structure, substituents, and functional groups present in the molecule, providing clarity and consistency, while common names often arise from historical or conventional usage. Mastery of both systems is important for effective communication in identifying and discussing compounds such as the alkynes.

Degree of Unsaturation

The degree of unsaturation helps determine the number of rings or multiple bonds in a molecule. For a compound with the molecular formula C6H10, the reduced hydrogen count compared to a completely saturated hydrocarbon indicates the presence of unsaturation—specifically, a triple bond in this case, which accounts for two degrees of unsaturation.

Alkynes

Alkynes are a class of hydrocarbons characterized by the presence of at least one carbon–carbon triple bond. This triple bond not only defines their reactivity but also affects their geometry, making them generally linear in the region of the triple bond. They follow a general formula where the number of hydrogens is reduced relative to alkanes, reflecting the unsaturation introduced by the triple bond.

Structural Isomerism

Structural isomerism refers to molecules that share the same molecular formula but differ in the connectivity of their atoms. In the context of C6H10 alkynes, different arrangements of the carbon chain and the location of the triple bond result in several isomers, each with distinct physical and chemical properties despite having the same overall formula.

Transcript

00:03 This question asks us to draw seven alkynes with the formula c6h10 and then give both iupac and common names for each one.

00:13 So to do these types of problems, i like to start off with the structures that are just straight chains with the alkyne in different positions.

00:22 So we'll start with putting the alkyne at carbon one.

00:24 So that is one, two, three, four, five, six.

00:29 There is the first structure.

00:31 We could put it at position two so one two three four five six or we could put it at position three so one two three four five six and those are all the unique straight chain alkyines that we can make out of six carbons then we can take one of the uh carbons off there and make it a methyl group so we'll have a five carbon chain now so let's start with position one again.

01:03 One, two, three, four, five.

01:05 And we can put that methyl group there.

01:09 One, two, three, four, five.

01:11 We could also put it here.

01:13 So those are unique.

01:15 And then we could also do a methyl substituent with the alkyne in the second position.

01:19 So one, two, three, four, five.

01:23 And we can have a methyl right there.

01:25 And then the last thing we can do is take that methyl group over here and put it onto this carbon.

01:32 So we have a carbon with three methyl coming off of it.

01:35 So that would look like this.

01:37 One, two, three, four, five, six.