Befuddled SN1 Nucleophilic Substitution Reaction

[linuxzhen]

BR-Ochem Part I Page 211 Example 3.25 choice C

SOS~~!!

explain SN1 reacton :(CH3)3CSH + (H3C)2CHOH2+--> (CH3)3CS+HCH(CH3)2 + H2O

is (CH3)3CSH the nucleophile ?

what's the structural formula of (H3C)2CHOH2+ I am totaly bewildering.

---

Members don't see this ad.

 

[PostBaccHopeful]

BR-Ochem Part I Page 211 Example 3.25 choice C

SOS~~!!

explain SN1 reacton :(CH3)3CSH + (H3C)2CHOH2+--> (CH3)3CS+HCH(CH3)2 + H2O

is (CH3)3CSH the nucleophile ?

what's the structural formula of (H3C)2CHOH2+ I am totaly bewildering.

Yes, all of that electron density on S will make (CH3)3CSH a good nucleophile. Because it is an Sn1 reaction, you will form a carbocation somewhere. H2O will leave from (H3C)2CHOH2+ and form a secondary carbocation; hence, this is why you have water as a byproduct. Since this is the most stable carbocation for this molecule, there will not be any rearrangement (H-shift, Methyl-shift, etc.).Next, (CH3)3CSH will act as the nucleophile and attack the carbocation to form (CH3)3CS+HCH(CH3)2.

Sorry, I don't know how to attach images otherwise I'd attach a drawing here.

 

[linuxzhen]

Yes, all of that electron density on S will make (CH3)3CSH a good nucleophile. Because it is an Sn1 reaction, you will form a carbocation somewhere. H2O will leave from (H3C)2CHOH2+ and form a secondary carbocation; hence, this is why you have water as a byproduct. Since this is the most stable carbocation for this molecule, there will not be any rearrangement (H-shift, Methyl-shift, etc.).Next, (CH3)3CSH will act as the nucleophile and attack the carbocation to form (CH3)3CS+HCH(CH3)2.

Sorry, I don't know how to attach images otherwise I'd attach a drawing here.

Is this reaction right? If not, correct my formula. 🙂

 

[PostBaccHopeful]

Is this reaction right? If not, correct my formula. 🙂

Overall, you got the idea. But, you should always draw your mechanisms step by step since the MCAT will never show reactions this way (please read my previous comment).
Btw, glad to know you figured out the structural formulas.

 

[PostBaccHopeful]

I figured it out..

 

[linuxzhen]

Overall, you got the idea. But, you should always draw your mechanisms step by step since the MCAT will never show reactions this way (please read my previous comment).
Btw, glad to know you figured out the structural formulas.

Do you mind teaching me how to attach images? That would be extremely helpful. Thanks! 🙂

1. click the "Attachments" button, Upload File from your Computer, then you will got the URL of you pic. ( If you already have an image on the web, ignore this step. )

2. click the "Insert Image" button, insert the URL you got.

3.Submit Reply

have a try~!