108 CHAPTER 2 An Introduction to Organic Compounds
b. Which takes up more space, the lone-pair electrons or the methyl group?
- How many ethers have the molecular formula Give the structural formula and systematic name for each. What are their
common names? - Draw the most stable conformer of the following molecule:
- Give the systematic name for each of the following compounds:
a. d.
b. e.
c.
- Calculate the energy difference between the two chair conformers of trans-1,2-dimethylcyclohexane.
- The most stable form of glucose (blood sugar) is a six-membered ring in a chair conformation with its five substituents all in
equatorial positions. Draw the most stable form of glucose by putting the OH groups on the appropriate bonds in the chair
conformer. - Explain the following facts:
a. 1-Hexanol has a higher boiling point than 3-hexanol.
b. Diethyl ether has very limited solubility in water, but tetrahydrofuran is essentially completely soluble. - One of the chair conformers of 1,3-dimethylcyclohexane has been found to be 5.4 kcal mol (or 23 kJ mol) less stable than the
other. How much steric strain does a 1,3-diaxial interaction between two methyl groups introduce into the conformer? - Calculate the amount of steric strain in each of the chair conformers of 1,1,3-trimethylcyclohexane. Which conformer would
predominate at equilibrium?
> >
O
tetrahydrofuran
CH 2 OH
CH 2 OH
OH
HO OH
HO
O O
glucose
CH 3 CHCHCH 2 CH 2 CH 2 Cl
Cl
CH 2 CH 3
CH 3 CH 2 CH 2 CH 2 CH 2 CHCH 2 CHCH 2 CH 3
CH 2
CH 3 CCH 3
CH 2 CH 3
CH 2 CH 3
CH 3 CH 2 CHCH 2 CHCH 2 CH 3
CHCH 3
CH 3
CH 3
CH 3 CH 2 CH 2 CH 2 CHCH 2 CH 2 CH 2 CH 3
CH 3 CCH 2 CH 3
CH 3
CH 3 CH 2 CHCH 2 CH 2 CHCH 3
NHCH 3 CH 3
CH 3
H 3 C CH 3
C 5 H 12 O?
N
N-methylpiperidine
CH 3
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