Room Temperature Acylketene Formation? 1,3-Dioxin-4-ones via Silver(I) Activation of Phenylthioacetoacetate in the Presence of Ketones

Abstract

Silver (I) activation of thioacetoacetates in the presence of ketones produces 1,3-dioxin-4-ones. Mechanistic studies addressing the intermediacy of an acylketene intermediate are described.

The Synthesis of Multifunctionalized 1,3-Oxazin-4-ones from Donor–Acceptor Cyclopropanes

“…To date the most widely used approach involves the cycloaddition of imines to acyl ketenes, which are often generated in situ . Recent literature describes a method to generate such acyl ketenes under mild reaction conditions and has subsequently proved useful for the synthesis of oxazinones, but the inherent electronic requirements of cycloaddition chemistry remain. Other methods to access 1,3-oxazin-4-ones include palladium-mediated carbonylations of α-diazo-β-dicarbonyl compounds and condensation reactions between hydroxyl amides and various carbonyl-containing compounds .…”

Iterative synthesis of nitrogen-containing polyketide via oxime intermediates

“…When we used NBS, 9 the starting material was consumed but complex mixture was obtained without the desired product (entry 3). While Cu( ii ) 10 a did not promote the intended reaction (entry 4), Ag( i ) 10 quickly converted the thioester and afforded the cyclized product with low yield (entry 5). This result seemed to be due to side reactions through ketene formation.…”

Does the Reaction of Cyclopropyl Acid Chlorides and Imines To Form 1,3-Oxazin-4-enone Heterocycles Proceed via a Ketene or an N-Acyl-iminium Mechanism?

“…First considered were the electronic effects. The originally disclosed use of acyl-thioesters 12 by Hoye et al showed the capacity for their reaction with ketones in the presence of silver trifluoroacetate to generate 1,3-dioxan-4-enones . These reactions were performed in chloroform, at room temperature, over 1.5 h (cf.…”