How to tell if a carbon is chiral?

[NameAlreadyTake]

The basic definition is whether or not the carbon is bonded to 4 different substituents. It's easy to tell a carbon is chiral if it's bonded to say Cl, H, N, and another carbon, but it seems like when it's bonded to more than one other carbon it becomes harder to tell. Sometimes you're supposed to look at what each other carbon is bonded to, to determine if it's chiral or not, and other times it seems like you're supposed to just ignore what the other carbons are bonded to? How do you know which one to do?

For example in the pic below, is the blue carbon considered chiral because carbon 1 is closer to the double bond (or anything else, ie a substituent) than carbon 2(making them nonequivalent carbons), or is the blue carbon achiral because it's just plain and simply bonded to 2 carbons?

---

Members don't see this ad.

 

[docelh]

A quick scan can usually tell you if the lengthy carbon substituents are different. If not, you have to go through the laborious process of seeing whether the carbon substituents are the same (they cannot be diastereomers or enantiomers).

RE: your example, your blue carbon is achiral because it is attached to two hydrogens given how you've drawn it.

 

[PhilIvey]

A quick scan can usually tell you if the lengthy carbon substituents are different. If not, you have to go through the laborious process of seeing whether the carbon substituents are the same (they cannot be diastereomers or enantiomers).

RE: your example, your blue carbon is achiral because it is attached to two hydrogens given how you've drawn it.

yep. I was going to say unless it specifies it can't be chiral because one would assume to H's to be attached in addition to the two carbons of the ring.

 

[Lacipart]

The basic definition is whether or not the carbon is bonded to 4 different substituents. It's easy to tell a carbon is chiral if it's bonded to say Cl, H, N, and another carbon, but it seems like when it's bonded to more than one other carbon it becomes harder to tell. Sometimes you're supposed to look at what each other carbon is bonded to, to determine if it's chiral or not, and other times it seems like you're supposed to just ignore what the other carbons are bonded to? How do you know which one to do?

For example in the pic below, is the blue carbon considered chiral because carbon 1 is closer to the double bond (or anything else, ie a substituent) than carbon 2(making them nonequivalent carbons), or is the blue carbon achiral because it's just plain and simply bonded to 2 carbons?

The Carbon you due has 2 Hydrogen bonded to it, so its not chiral.

Ignoring that though (lets say that blue carbon has a Cl attached to it), it would be chiral. I'm pretty sure the double bond on the far side makes the north and south carbon chains different, therefore chiral