What is true about the relationship between the following compounds? CH; CH3 CH; ČH3 ČH; CH3 A B All three are stereoisomers of each other. A and B are the same compound while C is a stereoisomer. All three are the same compound. A and B are the same while C is a conformer, all of the same compound. A and C are the same while B is a stereoisomer.

Draw the two chair conformations of the following compound A, and indicate which is more stable. СМез NH2 Ph A

most stable chair conformation of a Draw the most stable chair conformation of ring of compound

There are the two possible chair conformations of cis-1-ethyl-4-bromocyclohexane. What is the energy difference between the two chair conformations? Table 1. Steric Strain in Monosubstituted Cyclohexanes CN a The ON Col CHI CH.CH. CHICA GH SCHUL 0000 L-Drion Eag Calmel 01 0.12 0.25 0.25 0.30 0.70 0.90 0.95 11 13 2.8 kJ/mol 5.6 kJ/mol 6.0 kJ/mol 9.6 kJ/mol Kiwel 04 0.5 10 1.0 2.1

Classify each pair of compounds as either identical, constitutional isomers, stereoisomers, or not isomers.

Draw the two chair conformations of menthol, and tell which is more stable. 4-45 المركب بهيئتين الكرسي وتحديد أي الهيئتان أكتر استقرار CH3 Menthol HO CHICH3)2

HN- H3C HN -NH "CH3 OH H. CH3 H,C. Br H3C CH3 CH3 HO. Br HO,

Twist: 1H Draw the twist form of cyclohexane PART TWO: CHLOROCYCLOHEXANE 2A Draw the model of chlorocyclohexane 2B Is the chlorine axial or equatorial? 2C Draw the model of the flipped chair 2D Is the chlorine axial or equatorial? equato 2E Which conformation is more stable, the one with the chlorine axial or equatorial? 50 www.pearsoned.com RA026-0

Draw the conformer that would form after the back carbon of this conformer is rotated 60° rotation to the right (clockwise). H. H I CH3 H H C(CH3)3 Draw Newman Projection Q I I I I I I

Rank these conformations from least to most stable.