The well-known second-order perturbation method is used to correlate the bond-bond interaction constants in ground and excited electronic states of triatomic systems of the first-row elements, and unusual force constants in diazomethane and ketene with the effect of electron relaxation. The thirdand fourthorder perturbation schemes are used to determine qualitatively the contributions to the th...

Diphenylketene was generated in aqueous solution by flash photolysis, and rates of its decay accelerated by 30 bases of various structure were determined. The rate constants so obtained did not show the regular dependence on basic strength expected if the bases were serving as general base catalysts assisting the attack of water on the ketene, but they did vary with polarizability and steric bu...

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 ...

Elucidation of mechanisms and discovery of novel reactions are interconnected, as four research chapters from the Munich laboratory demonstrate. 1) In a new opening of the furan ring, 2-methoxyfuran and tetra-acceptor-substituted ethylenes furnish methyl acrylates, which are cis-3-substituted by a cyclopropyl ring that bears the four acceptor groups. Experiments with trans- and cis-1,2-bis(trif...

Second-order rate constants (k(Nu)) have been measured for the addition of amines to ketenes 4-6 in acetonitrile solution by the laser flash photolysis technique. These ketenes are formed from a photochemical Wolff rearrangement of diazoketones 1-3, respectively. For all diazoketones studied, the presence of amines as nucleophiles in the reaction medium results in the formation of an intermedia...

Iron-catalyzed alkylation of internal olefins, that is, α-oxo ketene dithioacetals, was successfully realized by using styrenes as the alkylating reagents. Highly functionalized tetrasubstituted olefins were prepared in moderate to high yields.

An efficient method for the synthesis of (+)-buergerinin F is established via the enantioselective aldol reaction of a tetra-substituted ketene silyl acetal with crotonaldehyde, followed by intramolecular Wacker-type ketalization.