Question

1. What is an ylide? How does it behave?
2. A pheromone of the female housefly is called muscalure. Look up the structure of
muscalure and devise its synthesis using the Wittig reaction.
3. What side products are generated during this reaction?
(trans-cinnamaldehyde + benzyltriphenylphosphonium -> 1,4-diohenyl-1,3butadiene)
During your analysis of the filtrate,
how many of these did you observe on the TLC plate? (2 spots observe)
4. What is the geometry about the double bond for the major product in this reaction? What
experimental data do you have to support your claim? Assign the E/Z designation to each
double bond.

Answer 1

Ans 1 :

Ylides are the compounds that are neutral in nature overall. These molecules have a carbon atom which is negatively charged and bonded to a positively charged atom such as sulfur , phosphorus etc.

These ylides can therefore be of various types : ammonium ylides , phosphorus ylides , halonium ylides , carbonyl ylides , oxonium ylides etc.

Ylides are very important category of molecules in organic chemistry as they behave to function as nucleophiles and help in preparation of various compounds that are of pharmacological importance.