Generation and C-Ethoxythiocarbonylation of Enolates Using Ultrasound

Abstract

O-Ethyl 3-oxothionoesters were obtained in good yields by reaction of O,O-diethyl trithiodicarbonate with enolate from ketones and NaH in tetrahydrofuran. The enolate formation and thioacylation were performed under ultrasonic irradiation.

Acylation of Esters, Ketones and Nitriles

“…Treatment of the dicyanide (184) with sodium hydride in DMSO gives, however, the cyclized product (185) resulting from the more hindered anion,22o a finding at variance with that usually observed in the Dieckmann reaction (Section 3.6.3.3.3.iii). As mentioned in Section 3.6.3.3.3.iv, cyclization of mixed cyano esters occur with the ester as electrophile and the cyanostabilized anion as nucleophile.…”

Bis(ethoxythiocarbonyl)sulfide

“…ethoxythiocarbonyl)sulfide also thioacylates carbon nucleophiles; its reaction under ultrasonic irradiation with a series of sodium enolates afforded 3-oxothionoesters in excellent yield (eq 5) 17. The title reagent was superior to S-ethyl O-ethyl dithiocarbonate or ethyl chlorothioformate.…”