AAMC Official Guide: OChem Question # 17

[TheRealAngeleno]

---

Members don't see this ad.

Hey guys so I was doing #17 of the OChem discretes and while I was reading the answer explanations, they were explaining how if the methine proton on C2 of (S)-2,3-dimethyloxazolidine was changed to a methyl group, the molecule would no longer be chiral. How could this be? The molecule seems to have no internal plane symmetry so I can't see how it would be achiral. Thanks a lot guys.

 

[MedChallenge]

Hey guys so I was doing #17 of the OChem discretes and while I was reading the answer explanations, they were explaining how if the methine proton on C2 of (S)-2,3-dimethyloxazolidine was changed to a methyl group, the molecule would no longer be chiral. How could this be? The molecule seems to have no internal plane symmetry so I can't see how it would be achiral. Thanks a lot guys.

Well, initially there are 4 different groups attached to C2, one of them being a methyl. Now if you take the proton off and add another methyl there in its place, there would be two methyl groups attached to C2 which would make it lose it's chirality.

Now, can you help me with nomenclature? I can't picture the structure that you named? I looked it up online, and found a similar molecule (2,2 or 2,4 instead of 2,3) but it looks like that molecule has an oxygen in the ring at the 3rd position. Where do you start numbering for that molecule and where on the ring are the two methyl groups?