ABSTRACT
We report herein facile acid-catalyzed isomerization of 1-(1'-cycloalkenyl)cyclopropyl sulfonates under mild conditions. The remarkable ease of ring opening is attributed to the presence of a 1'-alkyl substituent. Also included is a palladium-catalyzed ring opening reaction of 1-(1'-cycloalkenyl)cyclopropyl tosylates for convenient preparation of substituted 1,3-dienylamines, which complements previously reported nucleophilic substitution reactions of (1-vinyl)cyclopropyl tosylates.
Subject(s)
Acids/chemistry , Cyclopropanes/chemistry , Palladium/chemistry , Sulfonic Acids/chemistry , Catalysis , Molecular StructureABSTRACT
This review delineates several reported methods for the synthesis of isoprostanes and neuroprostanes with particular emphasis on the stereocontrolled construction of a suitably functionalized cyclopentane core. The alpha- and omega-side chains of these PG-like molecules are typically assembled by Wittig-type olefination reactions, standard transformations in the PG synthesis. The synthetic strategies include free radical cyclizations, a palladium-promoted coupling of three different components, an intramolecular cyclopropanation reaction-ring-opening sequence, a [2+2] photocycloaddition-ring-opening metathesis approach, and an intramolecular cross-coupling reaction of an alkyl iodide and a tethered alkenylsiloxane.
Subject(s)
Isoprostanes/chemical synthesis , Isoprostanes/chemistry , StereoisomerismABSTRACT
A new approach to isoprostanes and neuroprostanes featuring cis-dialkyl stereochemistry at the cyclopentane ring has been developed by employing an intramolecular cross-coupling reaction of an alkyl iodide and a tethered alkenylsiloxane for stereoselective installation of a functionalized omega-side chain.
