Question

Introduction: A description of the Wittig reaction, including the mechanism and driving force. See tex 1. 16.10, 10th Ed. Clearly draw the products showing stereochemistry (E vs Z) 2. RP=CH-CH3 + CH3-CH- R P=CH-CH3 Ph-CH-O R3P=CH-COOR CH3-CH=O

Answer 1

'vittig reaction : phosphorus ylldes react with aldehyde and ketones to introduce a cac double bond selectively in place of the conbonyl gustavi po : Reo + phoß-EH = ehe + R + alkone carbonyl. compound Dh ylide phosphorus phapo Tripheryl phosphine oxide phorus ylide used in this reaction is prepared by treatment of phosphonium sait with a base phosphorus ylide are neutral malocules having positive and centres on adjacent carbon atoms conected by a t-bond. 13 BY pha. -P- --> Ph R-Li. ph Pit Ch ph ph / php- ph Mechanism elle ph₂ p- hър- php - CH₂ RS OOR unohto onophospatane R Betaine 2 y =CH₂ + ph₂p=0

HE stereochemistry what is about stereochemistry of product alkene, El2 or sill/trans? But before that, check the following facty.. Note that contain ylides are highly stable. HE r phy georder Panz few more enample of such glides are: . in meiner Piping Söpina An unstable ylide tand normally to give 'z' isomer or eis-Isomer phuc zot phap ch "}_sphe ih his the . 'z'iyomer reaction is it However, with stable ylide selective p" ,=0 + php on the phao сно umes E 2 R3P=CH-CH3 + CH3-CH=0-> R₃P=CH-CH₂ + ph- chao. Hic Rup=CH-CooR + CH-CHEO ely-CHEO --- CAR