82,799 students have used Clutch for Orgo
97% got a better grade
3,804 minutes of Organic Chemistry videos

436 Video Solutions

Repeat Problem 3.40 for the stereoisomeric steroid skeleton having a cis ring fusion between the rst two rings. A typical steroid skeleton is shown along with the numbering scheme used for this class of compounds. Specify in each case whether the designated substituent is axial or equatorial. 

(a) Substituent at C-1 cis to the methyl groups 

Watch Solution

A typical steroid skeleton is shown along with the numbering scheme used for this class of compounds. Specify in each case whether the designated substituent is axial or equatorial. 

(a) Substituent at C-1 cis to the methyl groups 

Watch Solution

The following are representations of two forms of glucose. The six-membered ring is known to exist in a chair conformation in each form. Draw clear representations of the most stable conformation of each. Are they two different conformations of the same molecule, or are they stereoisomers that cannot be interconverted by rotation about single bonds? Which substituents (if any) occupy axial sites? 

Watch Solution

Specify reagents suitable for converting 3-ethyl-2-pentene to each of the following:

(g) 3-Ethylpentane 

Watch Solution

The heats of reaction were measured for addition of HBr to cis- and trans-2-butene.

Use these data to calculate the energy difference between cis- and trans-2-butene. How does this energy difference compare to that based on heats of hydrogenation (Section 6.3) and heats of combustion (Section 5.6)?

Watch Solution

Biological oxidation of hydrocarbons is a commonly observed process.

(a) To what class of hydrocarbons does the reactant in the following equation belong? 

What is its IUPAC name? 

 

Watch Solution

Oxidation of 4-tert-butylthiane proceeds according to the equation shown, but the resulting sulfoxide is a mixture of two isomers. Explain by writing appropriate sructural formulas. 

Watch Solution

Specify reagents suitable for converting 3-ethyl-2-pentene to each of the following:

(f) 2,3-Epoxy-3-ethylpentane 

Watch Solution

One of the following two stereoisomers is 20 kJ/mol (4.9 kcal/mol) less stable than the other. Indicate which isomer is the less stable, and identify the reason for its decreased stability.

Watch Solution

One stereoisomer of 1,1,3,5-tetramethylcyclohexane is 15 kJ/mol (3.7 kcal/mol) less stable than the other. Indicate which isomer is the less stable, and identify the reason for its decreased stability. 

 

Watch Solution

Identify the more stable stereoisomer in each of the following pairs, and give the reason for your choice: 

Watch Solution

Identify the more stable stereoisomer in each of the following pairs, and give the reason for your choice: 

Watch Solution

Specify reagents suitable for converting 3-ethyl-2-pentene to each of the following:

(e) 3-Ethyl-2-pentanol 

Watch Solution

Identify the more stable stereoisomer in each of the following pairs, and give the reason for your choice: 

 

Watch Solution

Specify reagents suitable for converting 3-ethyl-2-pentene to each of the following:

(d) 3-Ethyl-3-pentanol 

Watch Solution

Identify the more stable stereoisomer in each of the following pairs, and give the reason for your choice: 

(c) cis- or trans-1-Isopropyl-4-methylcyclohexane 

Watch Solution

Identify the more stable stereoisomer in each of the following pairs, and give the reason for your choice: 

(b) cis- or trans-1-Isopropyl-3-methylcyclohexane 

Watch Solution

Identify the more stable stereoisomer in each of the following pairs, and give the reason for your choice: 

(a) cis- or trans-1-Isopropyl-2-methylcyclohexane  

Watch Solution

Write a structural formula for the most stable conformation of each of the following compounds: 

Watch Solution

Specify reagents suitable for converting 3-ethyl-2-pentene to each of the following:

(c) 2-Bromo-3-ethylpentane 

Watch Solution

Write a structural formula for the most stable conformation of each of the following compounds: 

(f)  cis-1,1,3,4-Tetramethylcyclohexane 

Watch Solution

Write a structural formula for the most stable conformation of each of the following compounds: 

(e)  cis-1-tert-Butyl-4-ethylcyclohexane 

Watch Solution

Write a structural formula for the most stable conformation of each of the following compounds: 

(d)  trans-1-Isopropyl-3-methylcyclohexane 

Watch Solution

Write a structural formula for the most stable conformation of each of the following compounds: 

(c)  cis-1-Isopropyl-3-methylcyclohexane 

Watch Solution

Two alkenes undergo hydrogenation to yield a mixture of cis - and trans -1,4- dimethylcyclohexane. Which two are these? A third, however, gives only cis -1,4- dimethylcyclohexane. What compound is this? 

Watch Solution