The last installment of this series will explore the logistics of “dehydration of methylcycohexanols” as a collaborative experiments. The most straightforward collaboration would be to perform the “dehydration of methylcycohexanols” experiment in the same way and compare the relative yield of alkenes as measured by GC from different starting alcohols. Comparisons could be made with [...]
Besides the structure of the alcohol, what other variables may be explored?
1) One variable for this reaction that could be investigated is the nature of the catalytic acid. Aqueous acids, such as the 85% H3PO4 typically used for this experiment, contain some water which is also product of the reaction. I may also add that, [...]
The dehydration of methylcyclohexanols provides a fecund problem to explore. The key is to develop methods to determine the distribution of alkene products in terms of % total alkenes. There are four possible positional isomers: I. methylenecyclohexene (Aldrich, Acros 1192-37-6); II. racemic 3-methyl-1-cyclohexene (Acros, 591-48-0); III. 1-methyl-1-cyclohexene (Aldrich, Acros 591-49-1) IV. racemic 4-methyl-1-cyclohexene (Aldrich, Acros [...]
I want to pursue point #5 further by first grappling with the current literature concerning the “Evelyn Effect.” The JCE article by David Todd, “The Dehydration of 2-Methylcyclohexanol Revisited: The Evelyn Effect” observes a kinetic effect that can be explained by proposing that in a mixture of cis/trans 2-Methylcyclohexanol the cis isomer reacts much faster [...]
There are several advantages of studying the dehydration of methylcyclohexanols in the first semester of Organic Chemistry.
1) The experiment involves reactions that are typically studied during first semester: E1, E2, and the 1,2-hydride shift. It is a time-tested protocol that has been run in hundreds of labs by thousands of students.
2) Analysis of the experiment [...]
As predicted from the Journal of Chemical Education articles, three methylcyclohexene products were observed. Their relative abundance measured by peak height was 80, 16, and 4%. The alkene products represented by these peaks apparently correspond to 1-methycyclehexene, 3-methycyclehexene, and methylene cyclohexane respectively.
The dehydration of 4-methylcyclohexanol produce two products, that can be distinguished by our current [...]
A common Sophomore Organic Chemistry laboratory experiment that has great potential for further research is the acid catalyzed dehydration of simple alcohols. The classic dehydration of 2-methylcyclohexanol experiment that was introduced in Journal of Chemical Education in 1967 Taber(1967)JCE:44,p620. The rather simple procedure of distilling an alcohol with an aqueous acid has spawned several investigations [...]
There is currently a great deal of interest in using the information sharing capabilities of blogs, wikis, and discussion forums to promote undergraduate learning as well as to facilitate collaboration among scientists. In a recent article in Chemical & Engineering News entitled “Wired for Learning: Teachers are tapping into youths’ digital savvy to take science [...]
