What is a Wittig Horner reaction?
Wittig Horner reaction is a type of coupling reaction in which aldehydes or ketones couple with phosphonate-stabilized carbanions to give E-alkenes. This reaction was named after three scientists: Leopold Horner, William S. Wadsworth and William D. Emmons.
What is the difference between Wittig reaction and Horner Wadsworth Emmons reaction?
The Horner–Wadsworth–Emmons (HWE) reaction is a chemical reaction used in organic chemistry of stabilized phosphonate carbanions with aldehydes (or ketones) to produce predominantly E-alkenes….
| Horner–Wadsworth–Emmons reaction | |
|---|---|
| Organic Chemistry Portal | wittig-horner-reaction |
| RSC ontology ID | RXNO:0000056 |
Does Wittig work on esters?
The Wittig reaction is a popular method for the synthesis of alkene from ketones and aldehydes. However the Wittig reagent can tolerate many other variants. It may contain alkenes and aromatic rings, and it is compatible with ethers and even ester groups.
What is the modified Wittig reaction?
The Schlosser Modification of the Wittig Reaction allows the selective formation of E-alkenes through the use of excess lithium salts during the addition step of the ylide and subsequent deprotonation/protonation steps.
What is the synthetic importance of the Wittig reaction?
The Wittig reaction provides a path from aldehydes and ketones to alkenes, and consequently is a valuable tool in organic synthesis. For example, the Wittig reaction will convert an α,β-unsaturated ketone to a conjugated alkene.
Why is NaOH used in Wittig reaction?
In the second step, a base, such as sodium hydroxide (NaOH) or butyl lithium (BuLi), is used to deprotonate and forms the ylide (Wittig reagent). The ylide is used in the Wittig reaction. The ylide then acts as a nucleophile and adds to the carbonyl carbon. The overall reaction is given below.
Which of the following halides can be used in Wittig reaction?
[When planning a Wittig, it’s generally best to use a primary alkyl halide (or alkyl sulfonate) here, as secondary alkyl halides don’t work as well. ] The C-H bond adjacent to the phosphorus is relatively acidic [Note 2] and can be deprotonated with strong base to give the ylide shown.
What type of reaction is Wittig?
The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide (often called a Wittig reagent) to give an alkene and triphenylphosphine oxide.