title: A short and flexible route to tetrahydropyran-4-ones via conjugated nitrile oxides cycloaddition and oxa-Michael cyclization: a concise diastereoselective total synthesis of (±)-diospongin A.
abstract: A short and flexible [3+2+1] synthetic strategy was developed for the synthesis of substituted tetrahydropyran-4-ones, featuring [3+2]-cycloaddition of α,β-unsaturated nitrile oxides and alkenes and oxa-Michael cyclization in a 6-endo-trig fashion. The efficiency of this synthetic strategy was further demonstrated by the concise total synthesis of (±)-diospongin A in 8 steps with 20.2% yield.
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Yao
authors.forename: Jingyun
authors.initials: J
authors.lastname: Ren
authors.forename: Rongbiao
authors.initials: R
authors.lastname: Tong
mesh_terms: D000475:Alkenes / Q000737:chemistry; D003500:Cyclization; D061565:Cycloaddition Reaction; D009570:Nitriles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D011714:Pyrans / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000475:Alkenes; D009570:Nitriles; D010087:Oxides; D011714:Pyrans; C521317:diospongin A