title: Short and efficient synthesis of cryptophycin unit A.
abstract: [reaction: see text] Two short synthetic approaches toward cryptophycin unit A comprise a catalytic asymmetric dihydroxylation as the sole source of chirality, while all further stereogenic centers are introduced under substrate control. The key step of the first route is a vinylogous Mukaiyama aldol addition, which introduces the alpha,beta-unsaturated ester moiety with defined configuration at the delta-carbon atom. Likewise, allylation with allyltributylstannane diastereoselectively gives the homoallylic alcohol that can be converted by a metathesis reaction to a unit A precursor.
authors.affiliation: Department of Chemistry, Organic and Bioorganic Chemistry and Inorganic Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Eissler
authors.forename: Markus
authors.initials: M
authors.lastname: Nahrwold
authors.forename: Beate
authors.initials: B
authors.lastname: Neumann
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Stammler
authors.forename: Norbert
authors.initials: N
authors.lastname: Sewald
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D018360:Crystallography, X-Ray; D047630:Depsipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000447:Aldehydes; D047630:Depsipeptides; D010456:Peptides, Cyclic; C088419:cryptophycin