CHEM302 S09 CA2 key

CHEM302 S09 CA2 key - CHEM302, Spring 2009 Dr. Ruder 1...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Dr. Ruder 1 Class Activity 2 Reactions of Ethers and Epoxides Ethers are not very reactive but ring-strained epoxides react easily. Model 1: Ether Cleavage with HBr In the presence of strong acids like HBr and HI, ethers are cleaved to form alkyl halides. R O R' H Br + R O R' H + Br ROH + R'Br HBr RBr + H 2 O step 1 step 2 step 3 Questions 1. (a). What is the role of the ether in step 1 of Model 1 (nucleophile, electrophile, acid, base)? (b). Draw curved arrows to show electron movement for step 1. (c). What purpose does this first step serve and what is this process called? (d). Compare the reaction of an ether with acid (step 1) to the reaction of an alcohol with acid. Are there any differences? Explain. 2. For step 2 of the reaction shown in Model 1: (a). Draw curved arrows to show electron movement for step 2. (b). What is the leaving group in step 2? (c). Assuming that the R’ group is primary, by what mechanism does the reaction in step 2 occur (SN1, SN2, E1, E2, addition)? Explain. 3. In step 3 of the reaction shown in Model 1, the alcohol reacts with an additional equivalent of HBr to form an alkyl bromide. Draw the complete mechanism for step 3. 4. (a). The reaction of the phenyl ethyl ether with HBr is shown below. Draw the mechanism, using curved arrows to show electron movement. O
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

CHEM302 S09 CA2 key - CHEM302, Spring 2009 Dr. Ruder 1...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online