[iScience]

i have a silly question: so a chiral center has four distinct groups on it. but if that's the case, how can any carbon with a double bond be a chiral center? the maximum number of distinct groups you can have on it is three.

example:



how is the top carbon of the hexene a chiral center?

[discodermolide]

The top carbon of the ring is not a chiral centre.

[iScience]

this compound only has one chiral center which is at the bottom of the ring right?

also, it is in fact impossible for a double bonded carbon to be a chiral center right?

[discodermolide]

The chiral centre is at the bottom of the ring. The only one in this system. If you hydrogenate the top C=C then the top ring carbon will then be chiral.
Allenes can be chiral and they contain double bonds, but that is a special case.

[iScience]

even if the top is hydrogenated, i thought a chiral center required four different groups. a double bond means that two of the groups are the same doesn't it? so how can i get four distinct groups?

[discodermolide]

Draw the molecule without the top double bond and you should see that that C has 4 different substituents.