Sn1 rxn question

[OU11BB]

Which is true of Sn1 reaction?

a equal amounts of retention and inversion occurs
b complete inversion of configuration
c slightly more retention than inversion occurs
d slightly more inversion that retention occurs
e complete racemization occurs

I thought that we get a racemic mixture w/sn1 rxn. so i would lean to either E or A. Thanks.

---

Members don't see this ad.

 

[Loni]

I'm pretty sure that the answer is E, b/c with SN1, there is no inversion. That's SN2. With SN1, b/c a carbocation is formed, you always end up with a racemic mixture that is optically inactive.

 

[299678]

Which is true of Sn1 reaction?

a equal amounts of retention and inversion occurs
b complete inversion of configuration
c slightly more retention than inversion occurs
d slightly more inversion that retention occurs
e complete racemization occurs

In theory yes, but in practice complete racemization doesn't occur in SN1, rather slightly more inversion occur in SN1 (I know we learned it other way, but in practice, we don't control 100% over side reaction, so there will be more inversion than retension or racemization, just like Nitrogen inversion, we can't isolate each enantiomers since nitrogen does inversion so quickly)

so answer is d

 

[Bio Dental Mom]

I'm going to go with E also, since a carbocation intermediate forms, you get both S and R configurations.

 

[Maygyver]

Which is true of Sn1 reaction?

a equal amounts of retention and inversion occurs
b complete inversion of configuration
c slightly more retention than inversion occurs
d slightly more inversion that retention occurs
e complete racemization occurs

In theory yes, but in practice complete racemization doesn't occur in SN1, rather slightly more inversion occur in SN1 (I know we learned it other way, but in practice, we don't control 100% over side reaction, so there will be more inversion than retension or racemization, just like Nitrogen inversion, we can't isolate each enantiomers since nitrogen does inversion so quickly)

so answer is d

If the answer was d, it wouldn't be for this reasoning. I think the reasoning D could possibly be correct is that there is a slight steric hinderence if the reaction occurs fast enough. For example, there is a carbocation intermediate, however, if the nucleophile attacks very quickly, the leaving group may be blocking that side of the molecule so there would be a slightly larger amount of inverted product. I feel like for the DAT though the answer would be E.

 

[OU11BB]

the answer is D, i ran thru a chad video last night and he said that there is slightly more inverted product and this is because of hindrance from the leaving group. so hopefully this will not be a DAT question answer stem because it is kind of 2 answers.

 

[Maygyver]

the answer is D, i ran thru a chad video last night and he said that there is slightly more inverted product and this is because of hindrance from the leaving group. so hopefully this will not be a DAT question answer stem because it is kind of 2 answers.

Agree.

 

[299678]

Maygyver ! I advise you to learn more principle than just memorizing facts

 

[Maygyver]

Maygyver ! I advise you to learn more principle than just memorizing facts

You keep using that phrase. I advise you learn more principles too, because your principle is incorrect.

 

[UCB05]

My principal can beat up your principle.

Anyway, the logic is sound. It's like traffic diverting to the far lane down a two-lane road to avoid a bus parked in the shoulder lane.

 

[Maygyver]

My principal can beat up your principle.

Anyway, the logic is sound. It's like traffic diverting to the far lane down a two-lane road to avoid a bus parked in the shoulder lane.

I like it!

Sidenote: by Kpark's logic, SN2s wouldn't show inversion because the molecules would just instantaneously invert...

 

[299678]

Hey my friend Maygyver, textbook guy! I used the word, 'side effect' to explain the question. Nitrogen inversion is an another example that need to aware. Some student reject the fact that is not covered by the text book as you do.

There is people who is not qualified to be a medical student in terms of their immature attitude. Next time when you want to explain something, don't criticize or judge other people's comment. Just focus on a fact that you want to explain.

You still think that you are right? I strongly advise you to study more principle, not only textbook or solution manual, but also on broad perspective and Be mature !

 

[Maygyver]

Hey my friend Maygyver, textbook guy! I used the word, 'side effect' to explain the question. Nitrogen inversion is an another example that need to aware. Some student reject the fact that is not covered by the text book as you do.

There is people who is not qualified to be a medical student in terms of their immature attitude. Next time when you want to explain something, don't criticize or judge other people's comment. Just focus on a fact that you want to explain.

You still think that you are right? I strongly advise you to study more principle, not only textbook or solution manual, but also on broad perspective and Be mature !

Sorry, I can't really completely understand your post, but textbooks cover principle (I think you are trying to use the word concepts maybe?), and nitrogen inversion isn't needed to understand how SN1 reactions work.

 

[samurai361]

Nucleophilic attack can occur from either side of the plane, so the product might consist of a mixture of two stereoisomers. In fact, if the central carbon is the only stereocenter in the reaction, racemization may occcur. This stands in contrast to the SN2 mechanism, where the chiral configuration of the substrate is inverted. However, an excess of inversion is usually observed, as the leaving group can remain in proximity to the carbocation intermediate for a short time and block nucleophilic attack.

 

[loveoforganic]

Agree with D, lots of good explanations already!