Formation Of Quaternary Centers Research Articles

ChemInform Abstract: Formation of Quaternary Centers via the Michael Reaction. Electronic Compensation for Steric Congestion.

AbstractThe lithium enolates (I) undergo Michael addition to the acceptors (II), producing the adducts (III).

Formation of quaternary centers via the Michael reaction; electronic compensation for steric congestion

Formation of quaternary centers via the Michael reaction; electronic compensation for steric congestion

The invention of new radical chain reactions. Part 11. A new method for the generation of tertiary radicals from tertiary alcohols

A convenient procedure for the radical deoxygenation of tertiary alcohols has been invented using the double half esters of oxalic acid with the t-alcohol and N-hydroxypyridine-2-thione. Decomposition of this type of ester in the presence of 1,1-dimethylethane- or (better) 1,1-diethylpropane-thiol gave the corresponding hydrocarbons in good yield. It has been shown that the oxalate fragmentation is not concerted, but involves a stepwise loss of carbon dioxide. Tertiary alcohols are also a convenient source of radicals for addition to suitable alkenes with formation of quaternary centres.