title: Unified synthesis of C19-C26 subunits of amphidinolides B1, B2, and B3 by exploiting unexpected stereochemical differences in Crimmins' and Evans' aldol reactions.
abstract: The efficient synthesis of the C(19)-C(26) subunit of amphidinolide B(1) and B(2) has been completed using a boron-mediated aldol reaction. The synthesis of the C(19)-C(26) subunit of amphidinolide B(3) has also been accomplished through an unexpected anti aldol reaction using a titanium-mediated process. In addition, the first reported examples of a stereochemical discrepancy between the Evans' boron-mediated oxazolidinone and the Crimmins' titanium-mediated oxazolidinethione aldol reactions are disclosed. A working hypothesis is put forth to explain the results.
authors.affiliation: Department of Chemistry, 153 Gilbert Hall, Oregon State University, Corvallis, Oregon 97331, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Rich G
authors.initials: RG
authors.lastname: Carter
authors.forename: Alexandre F T
authors.initials: AF
authors.lastname: Yokochi
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis*; D002384:Catalysis; D007202:Indicators and Reagents; D018942:Macrolides / Q000138:chemical synthesis*; D008958:Models, Molecular; D015394:Molecular Structure; D000097442:Amphidinolides
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D007202:Indicators and Reagents; D018942:Macrolides; C062197:amphidinolide D; D000097442:Amphidinolides