Biomimetic Synthesis of Hitorins A and B via an Intermolecular Alkoxy Radical-Olefin Coupling Cascade

A biomimetic synthesis of hitorins A and B was achieved based on our modified biosynthetic proposal. In our synthesis, a radical cascade reaction between an alkoxy radical, generated from a hydroperoxide, and a monoterpene (+)-sabinene renders the tetrahydrofuran ring of hitorins A and B. In addition, experimental results supported that the oxidative cleavage of the tetrasubstituted olefin in a key intermediate is via a radical oxidation cascade followed by a Grob fragmentation.<br>

Biomimetic Synthesis of Hitorins A and B via an Intermolecular Alkoxy Radical-Olefin Coupling Cascade

A biomimetic synthesis of hitorins A and B was achieved based on our modified biosynthetic proposal. In our synthesis, a radical cascade reaction between an alkoxy radical, generated from a hydroperoxide, and a monoterpene (+)-sabinene renders the tetrahydrofuran ring of hitorins A and B. In addition, experimental results supported that the oxidative cleavage of the tetrasubstituted olefin in a key intermediate is via a radical oxidation cascade followed by a Grob fragmentation.<br>

Expedient Entry to 1-Aminoadamantane Derivatives via Aza-Prins Cyclization of 7-Methylenebicyclo[3.3.1]nonan-3-one Oximes

An efficient synthesis of 1-aminoadamantane (amantadine) derivatives is described. This synthesis features acid-promoted aza-Prins cyclization of 7-methylenebicyclo[3.3.1]nonan-3-one oximes, which are readily prepared from 1,3-adamantanediol via a Grob fragmentation and the subsequent oximation, to give various 3-substituted 1-(alkoxyamino)adamantanes. After the reduction of alkoxyamines, not only 3-substituted 1-aminoadamantanes, but also chiral 2,5-disubstituted derivatives were obtained in good yields.