quiz4-2006-2007

quiz4-2006-2007 - 2 CH 3 NBS, CCl 4 1 CH 2 CH 3 4 CH 2 CH 3...

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

View Full Document Right Arrow Icon
Quiz #4, Version 4.1, CHEM111, Fall Semester, 2006/2007 Student Name: Student ID #: Section: Note: You are required to complete all questions independently and reference materials such as textbook and lecture notes are not allowed. 1. NBS ( N -bromosuccinimide) is commonly used for preparation of allylic bromide. In bromination of the following alkene ( 1 ) by NBS in CCl 4 , however, the expected products ( 4 ) and ( 5 ) are not formed. Instead, two other compounds ( 2 ) and ( 3 ) are the bromination products. Write down the structures of these two products and predict which one is the major product (10 points). 2. Fill in the following blanks with chemical structures or appropriate reagents and reaction conditions in the following synthetic scheme. (16 points each blank). HO H PBr 3 CC Br D H 3 CO OCH 3 OCH 3 H 3 CO CH
Background image of page 1

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

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

Unformatted text preview: 2 CH 3 NBS, CCl 4 1 CH 2 CH 3 4 CH 2 CH 3 5 Br Br 2 3 3. (12 points) The reaction of methyl bromide with hydroxide ion produces methanol through an S N 2 mechanism. Draw the structure of the transition state. Is the reaction faster in the solvent of H 2 O or DMSO (dimethyl sulfoxide) ? Draw an energy diagram for the reaction in both solvents to rationalize your answer. 5. (12 points) The tosylate (OTos, a good leaving group) of ( 2R , 3S )-3-phenyl-2-butanol undergoes E2 elimination on treatment with sodium ethoxide (Na + -OCH 2 CH 3 ) to yield an alkene. Draw structures of the tosylate (in Newman projection), the transition state of the reaction, and the product. Please show stereochemistry where appropriate. CHCHCH 3 H 3 C OTos Na +-OCH 2 CH 3 Alkene...
View Full Document

This note was uploaded on 02/27/2010 for the course CHEM CHEM111 taught by Professor Dai during the Fall '06 term at HKUST.

Page1 / 2

quiz4-2006-2007 - 2 CH 3 NBS, CCl 4 1 CH 2 CH 3 4 CH 2 CH 3...

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