title: Synthesis of ovalicin starting from D-mannose.
abstract: [reaction: see text] A new synthesis of epoxyketone 22 is described that is a key intermediate in Barton's synthesis of ovalicin (2), a powerful anti-angiogenetic inhibitor. The key process for the construction of 22 was ring-closing metathesis of olefins 11 and 12 obtained from 2,3:5,6-di-O-isopropylidene-alpha-D-mannofuranose (4) and regioselective desilylation of tri-TES ether 19. Furthermore, an alternative stereoselective route from 22 into 2 has also been developed, and the overall yield of 2 from 4 was 10.0%.
authors.affiliation: RIKEN (The Institute of Physical and Chemical Research), Wako-shi, Saitama, 351-0198, Japan. shunyat@riken.go.jp
authors.forename: Shunya
authors.initials: S
authors.lastname: Takahashi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hishinuma
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koshino
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakata
mesh_terms: D008358:Mannose / Q000737:chemistry*; D008968:Molecular Conformation; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D012717:Sesquiterpenes; C002781:ovalicin; D008358:Mannose