Question

How many chiral centres are in the penicillin molecule?

Answer 1

If I exclude the `R` group, I count `7`.........

Explanation:

Starting from the amide `NH`, and going clockwise, I count `NH^1`, `""^1HNCH^2`, `H^3CS`, `CH_3^4`, `CH_3^5` (the methyls are diastereotopic), `NCH^6`, `OH^7`. And thus there are `7`. Do you agree?

If I could label the diagram I would, but I have not got the wherewithal at the moment.