title: Total synthesis of (±)-cafestol: a late-stage construction of the furan ring inspired by a biosynthesis strategy.
abstract: An efficient bioinspired approach to the total synthesis of (±)-cafestol features a late-stage installation of the furan ring with a mild Au-catalyzed cycloisomerization. The Et2AlCl-promoted aldehyde-ene cyclization and subsequent Friedel-Crafts reaction deliver a requisite tricyclic system in gram scale with high stereo- and regioselectivity. Moreover, a highly stereoselective SmI2-mediated aldehyde-alkene radical cyclization furnishes the key bicyclo[3.2.1]octane skeleton to offer an advanced intermediate for the synthesis of other oxygenated ent-kaurene diterpenoids.
authors.affiliation: CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhu
authors.forename: Jisheng
authors.initials: J
authors.lastname: Luo
authors.forename: Ran
authors.initials: R
authors.lastname: Hong
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000475:Alkenes / Q000138:chemical synthesis; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D017612:Gold Compounds / Q000737:chemistry; D015394:Molecular Structure; D009795:Octanes / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D000475:Alkenes; D004224:Diterpenes; D005663:Furans; D017612:Gold Compounds; D009795:Octanes; C038016:gold chloride; C053400:cafestol; C039281:furan; C026728:octane