Question

Explain why it is possible to generate a ylid with aqueous sodium hydroxide

Answer 1

It is possible to generate ylid with aqueous solution of NaOH because it gives cation. Simple phosphorenes are very reactive and are unstable in the presence of moisture and oxygen in the air. They are therefore prepared in a super dry solvent. More stable phosphoranes are obtained when the ylid contains a group that can stabilize the negative charge from the carbanion. For example: Ph3P=CHCO2R and Ph3P=CHPh. From the phosphonium salts, these reagent are formed more readily, requiring only with NaOH, and they are usually more air-stable. They usually give rise to an E-alkene product when they react, rather than the more usual Z-alkene.