Ramelteon is a hypnotic agent used in the treatment of insomnia:
(b) How many sp3-hybridized carbon atoms are present in this structure?
Alright, let's see how many of these carbon atoms are sp3 hybridized, so what I'm going to do is, I'm going to paste in our structure, right? here it is and now we need to look at how many of our carbons are SP3 hybridized. Remember, if it's sp3 hybridized, right? We know it's to have 4 Sigma bonds, right? Four single bonds attached to different atoms, right? Does it have to be different, but just four atoms, so let's take a look. Now, notice that those double bonds there, those are actually not going to be attached to 4 atoms, right? Because those have a PI bond. So, maybe we should be looking at the carbon atoms that are single bonded, so we know this is going to have two hydrogens coming off it, we can say that one's sp3, same thing here, right? Two hydrogens coming off, so that's 4 Sigma bonds we can call this one 3, this one 4, right? here notice that there's going to be a hydrogen coming off, so we can call this 5, here we know that this one's going to be 6 right here, this is going to be 7 and we can say that we have 8 and 9, at all these locations we're going to have 4 Sigma bonds coming off of that carbon. So, in total we should conclude and then we have 9 sp3 carbons. Alright guys I just showed you at all the locations that where they appear. Alright guys, so hopefully that made sense.