Organic Chemistry Synthesis/Mechanism

[YachtZ]

Homework Statement

Problems: http://imgur.com/qN7Iq

Homework Equations

n/a

The Attempt at a Solution

For the synthesis, I tried opening the epoxide with HBr and then adding OMe- in HOMe to substitute the Br with the OMe group in the product. However, I am unsure how to substitute the alcohol (from the epoxide opening) into the ethyl group (my friend also suggested Grignard's, but I'm not familiar with tha reaction). For the mechanism problem, I can't seem to figure out how a double bond can be formed on the 3-4 carbon bond, since an elimination on the Br would leave a double bond on the 2-3 bond. I might be completely off the right track, so I appreciate any help on the issue. Thanks!

 

[nate808]

Hello,
For the synthesis problem, you are on the right track with using HBr to open the epoxide and then substituting the Br with a OMe group. To substitute the alcohol into the ethyl group, you can use a Williamson ether synthesis reaction. This involves reacting the alcohol with a strong base (such as NaOH) to form an alkoxide ion, which can then react with an alkyl halide (such as ethyl bromide) to form the ether product. As for the mechanism problem, it is possible to form a double bond on the 3-4 carbon bond by performing an E2 elimination reaction. This involves using a strong base (such as NaOH or KOH) to remove the Br group and form a double bond on the adjacent carbon. I hope this helps! Let me know if you have any further questions.