title: Cascade polycyclization: exploration of a convergent route to access various tricyclic and tetracyclic products related to sterols.
abstract: The expedient synthesis of tricyclic and tetracyclic compounds via a cascade polycyclization methodology is described. Nazarov substrates (II) containing two Michael acceptors and a cyclohexenone ester (I) underwent cycloaddition followed by intramolecular 1,4-addition to furnish, in a highly stereoselective manner, tricyclic and tetracyclic products (III). Such compounds are interesting intermediates for the synthesis of polycyclic natural and unnatural products.
authors.affiliation: Département de Chimie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12(e) Avenue nord, Sherbrooke, Québec J1H 5N4, Canada.
authors.forename: Benoit
authors.initials: B
authors.lastname: Guay
authors.forename: Pierre
authors.initials: P
authors.lastname: Deslongchamps
mesh_terms: D001685:Biological Factors / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D007202:Indicators and Reagents; D011083:Polycyclic Compounds / Q000138:chemical synthesis*; D013261:Sterols / Q000138:chemical synthesis*
chemical_list: D001685:Biological Factors; D007202:Indicators and Reagents; D011083:Polycyclic Compounds; D013261:Sterols