CHE 201LLR Lecture Notes - Lecture 7: Reagent, Cyclopentane, Stereochemistry

• School: University at Buffalo
• Department: Chemistry
• Course: CHE 201LLR
• Professor: elizabeth clizbe

Document Summary

A monocyclic compound is one that contains a single ring. Relative stabilities are determined from heats of formation. All monocyclic alkanes have the same empirical formula: stabilities can be compared on a per carbon basis. Heat of combustion also allows relative stabilities of cycloalkanes to be measured: lowest heat of combustion per 2 = most stable. Tetrahedral carbons want a bond angle of 109. 5 . Angle (baeyer) strain refers to the strain present when the bond angle is not 109. 5 : does not allow optimal overlap. Cyclopropane has the highest angle strain with bond angles about 60 . Other cycloalkanes bend, twist and pucker out of being planar to minimize strain. Cyclohexane is the most widely occurring ring compounds of nature origin. Has the same stability as a typical unbranched alkane. Has bond angles very close to the ideal 109. 5 . This avoids angle strain and torsional strain. There are two types of hydrogen atoms.