title: A Shimizu non-aldol approach to the formal total synthesis of palmerolide A.
abstract: A formal total synthesis of palmerolide A has been accomplished by assembling three fragments by means of successive Julia-Kocienski olefination, Yamaguchi esterification, and ring-closing metathesis (RCM). Our initial efforts to combine the first two fragments through a Julia-Kocienski reaction between a secondary sulfone and a ketone were not successful; nevertheless, it was feasible between a primary sulfone and aldehyde. Yamaguchi esterification with the third fragment then set the stage for a RCM reaction. Initial failure of the RCM with a PMB-ether adjacent to the olefins and the difficulty in cleaving the PMB-ether prompted us to change the choice of protecting groups, which then paved the way to the macrocyclic core of palmerolide A.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Bombay, Powai, Mumbai-400076, India.
authors.forename: Sandip A
authors.initials: SA
authors.lastname: Pujari
authors.forename: Parthasarathy
authors.initials: P
authors.lastname: Gowrisankar
authors.forename: Krishna P
authors.initials: KP
authors.lastname: Kaliappan
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000970:Antineoplastic Agents / Q000032:analysis / Q000138:chemical synthesis* / Q000737:chemistry*; D045744:Cell Line, Tumor; D004951:Esterification; D006801:Humans; D018942:Macrolides / Q000032:analysis / Q000138:chemical synthesis* / Q000737:chemistry*; D008545:Melanoma / Q000503:physiopathology; D008968:Molecular Conformation
chemical_list: D000475:Alkenes; D000970:Antineoplastic Agents; D018942:Macrolides; C522534:palmerolide A