Studies on Ketene and Its Derivatives. LIV. Reaction of Diketene with Ketene Acetals

Gallium tribromide catalyzed coupling reaction of alkenyl ethers with ketene silyl acetals.

A domino pericyclic route to polysubstituted salicylic acid derivatives: four sequential processes from enynones and ketene silyl acetals.

Alkenyl alkynyl ketones and ketene silyl acetals (KSAs) undergo regioselective [2+2]-cycloaddition under thermal conditions, triggering domino pericyclic reactions en route to various poly-substituted salicylic acid derivatives.

Action of Ketene on Gonadotropic Hormones*

Ketene has been found to be a highly specific,acetylating agent for aqueous solution of proteins. It reacts only with amino, thiol, and phenolic hydroxy groups (1). Several investigators (24) have shown that the primary amino groups react most rapidly, while the hydroxy groups of tyrosine are acetylated at a much slower rate. The hydroxy groups in carbohydrate radicals of the protein molecule d...

Enantioselective acylation of silyl ketene acetals through fluoride anion-binding catalysis.

A highly enantioselective acylation of silyl ketene acetals with acyl fluorides has been developed to generate useful α,α-disubstituted butyrolactone products. This transformation is promoted by a new thiourea catalyst and 4-pyrrolidinopyridine and represents the first example of enantioselective thiourea anion-binding catalysis with fluoride.

A Convenient Ketene Generator

A simple apparatus for the preparation of ketene (CH,--C =O) from acetone vapor is described by Ott, Schr6ter, and Packendofff (1). A more rigid and convenient apparatus has been designed and used by the writer (Fig. 1). Pyrex glass used in both the filamentsupport and bulb reduces the possibility of cracking or breaking. The removable filament-support makes it possible to replace the filament ...