General Synthesis of Ketones from Carboxylic Esters and Carboxamides by Use of Mixed Organolithium-Magnesium Reagents: Syntheses of Artemisia Ketone

Article abstract of DOI:10.1002/hlca.19870700710

The novel reagents formed by combination of Grignard reagents (RMgX) with lithium diisopropylamide (LDA) convert non-enolizable carboxylic esters or carboxamides into ketones which are protected from further reaction by their in situ conversion into enolates.These enolates can be trapped with electrophiles such as Me3SiCl and allyl bromide.The scope of this Grignard mono-addition is illustrated by two direct synthesis of artemisia ketone (14).