Acetic Anhydride → Lithium Hexamethyldisilazide

Participants

Reaction Steps

A solution of lithium hexamethyldisilazide was prepared by the addition of 5.12 ml of a 1.6M solution of n-butyllithium in hexane to 1.75 ml of hexamethyldisilazane in 25 ml of dry THF at -10° with stirring, under argon. The solution was cooled to -78° and added by cannula to 1.57 g of 4-nitrobenzyl 2-(4-allylthioazetidin-2-on-1-yl)acetate in 12 ml of dry THF at -78°, with stirring under argon. After 5 minutes 0.846 ml of carbon-disulphide was added by syringe. 1.77 ml of acetic anhydride were then added, followed by 1.07 ml of glacial acetic acid. The solution was allowed to warm to room temperature and evaporated to leave an orange oil.

Provenance & Evidence