title: Studies on a urea-directed Stork-Crabtree hydrogenation. Synthesis of the C1-C9 subunit of (+)-zincophorin.
abstract: A detailed account on the stereoselective synthesis of the C1-C9 subunit of (+)-zincophorin is described here. This approach features the first application of a stereoselective inverse electron demand hetero-[4 + 2] cycloaddition of chiral allenamides in natural product synthesis. The C1-C9 subunit matches Cossy's intermediate, thereby constituting a formal total synthesis. In addition, details of an unusual urea-directed Stork-Crabtree hydrogenation observed during these efforts are also disclosed here.
authors.affiliation: Division of Pharmaceutical Sciences and Department of Chemistry, Rennebohm Hall, 777 Highland Avenue, University of Wisconsin, Madison, Wisconsin 53705, USA.
authors.forename: Zhenlei
authors.initials: Z
authors.lastname: Song
authors.forename: Richard P
authors.initials: RP
authors.lastname: Hsung
authors.forename: Ting
authors.initials: T
authors.lastname: Lu
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Lohse
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D006865:Hydrogenation; D008958:Models, Molecular; D008968:Molecular Conformation; D011422:Propionates / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism; D014508:Urea / Q000737:chemistry*
chemical_list: D011422:Propionates; D014508:Urea; C043279:zincophorin