215F07-notes-9-24-07

215F07-notes-9-24-07 - Chem 215 F07 Notes Dr Masato Koreeda...

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

View Full Document Right Arrow Icon
– Dr. Masato Koreeda - Page 1 of 4. Date: September 24, 2007 Chapter 14 Aldehydes and Ketones: Addition Reactions at Electrophilic Carbons Overview of Chapter 14 1. Structures of aldehydes and ketones C R R' O R, R' = alkyl, aryl: ketones R = alkyl, aryl; R' = H: aldehydes ! ! electrophilic C Aldehyde C=O carbons are less sterically hindered and more electrophilic compared with the corresponding ketone carbons (i.e., with the same R) lone pair: more basic than C=O " 2. Reactions of aldehydes and ketones with an electrophile and a nucleophile C R' R O !" framework lone pairs all of these sigma-bonds and lone pairs on the same plane El + with this trajectory # -bonding Highest occupied molecular orbital (HOMO) C R' R O empty anti-bonding orbitals Lowest unoccupied molecular orbital (LUMO) Nu: trajectory of a nucleophile approach trajectory angle of 107° C R' R O Nu C R' R O Nu sp 3 between sp 2 and sp 3 ; on its way to sp 3 C R R' O El all atoms including El on the same plane 3. Activation of RR’C=Z (Z = O and N) with H-A or a Lewis acid activates C=O toward a nucleophilic addition O O H A becomes even more ! ; i.e., more electrophilic O H A H A Lewis acid (L.A.) O L.A. O
Background image of page 1

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

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

This note was uploaded on 04/01/2008 for the course CHEM 215 taught by Professor Koreeda during the Fall '07 term at University of Michigan.

Page1 / 4

215F07-notes-9-24-07 - Chem 215 F07 Notes Dr Masato Koreeda...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online