Edit

dlarsen says:

Take a look at the "nomenclature of alkanes" module as a reference for format and completeness.

Aleksandra Milman says:

For the section that says problems: For numbers 1-4, you provide nice structures, but you do not give any instructions as to what you want us to do with them. Adding, something like Name the Following would be helpful.

Aleksandra Milman says:

When you say:
"Here is a chart containing the systemic name for the first twenty straight chain alkene."
You should change alkene to alkenes.

Lauren Rice? says:

Overall, this is a very good explanation of how to name alkenes. I liked how you included the table of the alkene chains and you're diagrams are good as well.

At the beginning you mentioned that the molecular formula of an alkene is the same as a cyclic ring. You might want to explain what a cyclic ring is or perhaps include a picture of one.

When you talk about the structure of the alkene you might want to explain a little more about sp2 hybridization and what exactly that means. Maybe you could talk about how to determine if something is sp2 or sp3, etc.

Watch out for spelling errors, in part ii of the naming process you need to correct your spelling of your and you need to add which functional groups receive a higher priority over alkenes such as -OH.

I would give a short description of what stereoisomers are and I would maybe include a picture of one so the reader knows what you're referring to.

When you're talking about the E,Z method of naming, you should maybe include a few sentences about how to determine the priority of a substituent. For instance, molecules that have a higher molar mass have a higher priority.

Also, not all of your problems are showing up, so just make sure that they are visible to the reader. Also, you might want want to add some other sources maybe another text book besides the one we use in our class.

- Lauren Rice and Samantha Spragg

Anhthu Do says:

I thought your diagrams were well done. However, I would recommend paying more attention to spelling, grammar, and overall formatting. For example, instead of "sp2," it would be more appropriate to superscript the 2. I can see some misspelled words like "hydroxly" instead of "hydroxyl." Some words are also unnecessarily capitalized. Your article would look more polished if these little details were addressed. For, "The Basic Rules" part i, it would be nice if you included an example of "a tie for longest carbon chain" and "the most substituted chain." What does it mean to be more substituted? How do I decide which chain is more substituted? I also agree with previous commenters that you should include more descriptions for your rules, especially when telling the reader that they need to identify stereoisomers. If you choose to not go into depth about stereoisomers, cis/trans, and E/Z conformations, perhaps you could link to other articles. Good job! You have a nice foundation, and now you just need to build on it.

Pwint Zin says:

Suggestions:

Please explain why we can't use cis-trans and why it has to be E-Z. You said "On the other hand if there are 3 or 4 non-hydrogen atoms attached to the alkene then use the E, Z system". This isn't so. It's possible that those 3 or 4 non hydrogen atoms are all "Br" then what? They all have the same priority so can you still use E-Z rule?

I would futher enhance your definition of E-Z rules for someone who has no knowledge of it. For example, you said "Z (zusammen) means the higher priority groups are on the same side. (Zame Zide)." Same side compared to what? I would explain that it is relative to the double bond.

"Zame Zide" might be confusing for people so you might want to explain that it is a trick to memorizing it.

Also explain what the higher priorities are. What are higher priorities? What has higher priority compared to what?

Remember that you are writing a section of a textbook so I wouldn't use words like "weird".

You explained that if you have an alcohol substituent, you end in -enol, so might want to explain what else would influence the ending name besides alcohol.

Since you don't have much depth in the introduction, please explain how and why alkenes are important and explain their relevance to life.

Jennifer Lew? says:

Great job covering your topic. There are some modifications that you can make to clarify and complete your module.

Under the heading, “Structure of Alkenes,” you mention that an alkene consists of a pi and sigma bond due to the overlap of specific orbitals. In the corresponding figure, you could include the sp2 orbitals to show the sigma bond and also label the p and sp2 orbitals.

In naming alkenes, it is also important to mention that the position of the double bond is indicated by the first alkene carbon (C1) located on the end of the parental chain closest to the double bond. For example, you could clarify the difference in numbering between 1-Butene and 2-Butene.

To help aid in your discussion of naming rules, you should also include several example alkenes, each numbered the correct way with their proper IUPAC name. You should also mention where the number corresponding to the substituents belong in the proper name. For example, the position of the double bond is indicated by placing the number before the name of the parent chain. Additionally, the position of the alcohol substituent in an alkenol is indicated by placing the number immediately before the “ol” in the parent chain (eg. CH2=CHCH2OH is 2-propen-1-ol).

In identifying E/Z isomers for trisubstituted or tetrasubstituted double bonds, it would be helpful if you provided an additional image displaying Z-isomerism. Indicate in the image where the 2 higher priority sustituents are so that it is obvious for the reader that the substituents are on the same side. You could also modify your E isomer image in this manner. Also, if you do not want to include the rules for determining the priority of substituents, you could provide a link to a site that explains R/S stereochemistry, as the priority rules are the same.

If you clarified the naming rules and added more details, it would be easier for a reader who is new to this topic to understand. Great job!

Lyudmyla Demyan? says:

Great job on your module! Rules for naming are really good organized, however add some more examples. For example, next to E-Z rules add at least one example for each rule and also you might use different colors to make it easy to understand. Provide some examples for common names and add hyperlinks to the key words as cis, trans et.
For E-Z rules it is also important to mention about priority, how to identify lower and higher priority.In the rule II, point "a" is not true if there are other functional groups with higher priority.
Practice problems are great, but add some more. edited 15:10, 9 Mar 2009

Elise de Gandiaga? says:

First off, good job Sharamatha. Your module was very easy to follow.

There were however a few problems that just need more clarification. For example, you mention that an alkene is an unsaturated hydrocarbon. It might be helpful to define what that is or you could just make that into a link for another chem-wiki (if there is one).

Also, for rule number four where you explain cis and trans, it might be clearer if you add in the hydrogen’s and then color code the two substituents that you are referring to. I understand what you are saying, but someone who is new to o-chem might not be able to follow what you are saying. The same goes for rule number five. You should add some color to the substituent’s that you are addressing that way it’s easier to follow.

Another thing you might want to consider would be looking at other journals for references and examples. I think you have to have at least two. The library would be a great place to find these (just go on-line to their reference site). Other than that, I really liked your module!