Organic chemistry SN1 reaction's

[physstudent1]

Homework Statement

Find the major organic product B of http://www.webassign.net/userimages/kasandbe/CH221_ssii_02/CH221_exam2_ssii_02_7a.gif

(with ethanol at 0 degrees Celsius)

Homework Equations

The Attempt at a Solution

I thought that since it is a SN1 reaction the -OTs would be the LG and that -OCH2CH3 would connect to the carbon it was on and form a racemic mixture but this isn't the right answer can anyone clear this up I seem to be confused? Thanks.

 

[chemisttree]

That's certainly possible but only as a minor product. You will note that in this SN1 reaction, OTs^- is indeed the leaving group. Study the carbonium ion that results. It is a secondary carbonium ion next to a 3^o carbon and a 1^o carbon. What might happen?

 

[Blueshift5]

In an SN1 reaction, the leaving group (-OTs in this case) will dissociate first to form a carbocation intermediate. The nucleophile (ethanol) will then attack the carbocation to form the product. In this case, the product B would be 1-ethoxy-2-methylcyclohexane. It is important to note that in an SN1 reaction, the stereochemistry of the product is not important, so a racemic mixture can form. However, in this specific case, the product does not have any chiral centers, so a racemic mixture would not be formed. The -OTs group is not involved in the final product, it is simply a leaving group in the reaction. I hope this clears up any confusion.