title: Total synthesis of (+)-quassin.
abstract: A total synthesis of (+)-quassin from naturally occurring (S)-(+)-carvone is described. The total number of steps was 28, and the overall yield was about 2.6%. The synthetic strategy for the construction of the tetracyclic carbon framework was based on a C-->ABC-->ABCD ring annulation sequence, involving an aldol reaction, an intramolecular Diels-Alder reaction, and an intramolecular acylation as the key steps. Subsequent functionalization of ring A and ring C then afforded the target (+)-quassin.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong. tonyshing@cuhk.edu.hk
authors.forename: T K
authors.initials: TK
authors.lastname: Shing
authors.forename: Q
authors.initials: Q
authors.lastname: Jiang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis*; D005900:Glaucarubin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D036702:Quassins; D013237:Stereoisomerism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D007202:Indicators and Reagents; D036702:Quassins; D005900:Glaucarubin; C010317:quassin