Notes Aldehydes and Ketones - Notes Aldehydes and Ketones...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
O C Notes Aldehydes and Ketones The major similarity between an aldehyde and a ketone is the carbonyl group. A carbonyl group is a carbon atom doubly bonded to an oxygen atom. C O Both molecules have a carbonyl group, the difference the number of carbons bonded to the carbonyl carbon. An aldehyde will have none or one and a ketone will have two carbons. All aldehydes, except formaldehyde, will have a hydrogen atom on one side of the carbonyl carbon and at least on carbon on the other side. C O H R All ketones have a carbon on each side of the carbonyl carbon. C O R R Remember that the ‘R’ symbolizes any carbon side-chain, from one to a million carbons. Basically, what it comes down to is that in an aldehyde the carbonyl group is on the terminal (last) carbon and the ketones carbonyl group is not. These compounds are found at the most fundamental levels of biological existence. Glucose is the single most important molecule in providing energy at a cellular level. Without glucose you would die in seconds. Glucose, the most important carbohydrate, not only has a carbonyl group but is an aldehyde. Another common carbohydrate is fructose, fruit sugar, this compound is a ketone. These compounds are more reactive than your typical alkane, the question you may ask is why? The answer lies in the location of the electrons in the carbonyl group. First, look at the hybridization of a carbonyl carbon. A carbon connected to three other molecules must be doubly bonded to one of those molecules. For a double bond to form p-orbitals must overlap over a sigma bond. The hybridization loses one p-orbital, leaving the carbon as sp 2 , allowing the formation of the other bond with the free p-orbital, forming a pi-bond. Back to our question, why are the aldehyde and a ketone more reactive than an alkane. When the pi-bond forms the electrons in this molecular orbital are more exposed, making them more vulnerable to reacting. Try to visualize the electrons sticking out on each side of the bond, leaving them accessible to other compounds.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern