Summary: CHM 7200 Organic Structures and Mechanisms Fall Term 2005
Problem Set 1: This problem set is now available at (www.blackboard.wayne.edu). It will be due in
class 7 days (09/16/05) from today (09/09/05). Grades will be administered as follows: 5 (exceptional
effort), 4 (complete), 3 (incomplete or inadequate effort), 2 (poor effort), 0 (nonexistent). No late problem
sets will be accepted.
1. Problem: Consider the structures XCH2­OH where X = OCH3 and F. What is the most
favorable conformation of each molecule? Illustrate the dihedral angle relationship along the C­O
bond. Why is it the most favorable conformation? Explain using FMO principles learned in class.
Answer:
Fluoromethanol F-CH2OH
Methoxymethanol MeO-CH2OH
The most favorable conformation of the molecules listed above can be accounted for by the anomeric
effect. In the case of fluoromethanol, where an oxygen lon-pair is anti to fluorine, the conformation
having the hydroxyl hydrogen GAUCHE to the fluorine is preferred.
H O
F
H
H
Gauche
H O

Source: Andreana, Peter R. - Department of Chemistry, Wayne State University

Collections: Chemistry