[cheshplja]

Hi. I have a problem and I need help solving it.

I have this molecule, which is a male produced sex pheromone (component) of a beetle. I know that it (3,5-dimethyl-6-(1-methylbutyl)-pyran-2-one) is chiral and I've identified the chiral center. But I'm an ecologist, not a chemist and it's been a few years since I've attended organic chemistry classes. Can you guys help me determine which of the bottom two in the image is the S and R enantiomer and an explanation would be welcome as well. Did I even draw these correctly?

Thank you in advance.

[Hunter2]

The left molecule is S and the right one R configurated. Exchange the substituents that hydrogen is on bottom. H with Methyl and Ethyl with the pyranering. Order is pyrane, Ethyl, Methyl.

[cheshplja]

Thanks for your help. Much appreciated

[clarkstill]

The left molecule is S and the right one R configurated. Exchange the substituents that hydrogen is on bottom. H with Methyl and Ethyl with the pyranering. Order is pyrane, Ethyl, Methyl.

Don't you mean left is (R)?

[Vidya]

Yes - left is R and right is S