title: Stereoselective synthesis of the C13-C22 fragment of callystatin A by a non-aldol approach.
abstract: An efficient synthetic route to the C13-C22 subunit of callystatin A is reported. The key features include diastereoselective alkylation, using Myers auxiliary, for the preparation of the three carbon synthon 7, stereo- and regioselective oxidative vicinal functionalization of an electron deficient trisubstituted (Z)-olefin using an intramolecular sulfinyl group as the nucleophile, diastereoselective radical debromination of a bromohydrin derivative using Guindon's protocol to prepare the C16-C18 anti-anti stereotriad, Lewis acid promoted crotylation following Keck's protocol to create C19, C20 stereocenters and the use of the Pummerer reaction to reveal an aldehyde for the extension of two carbons by Wittig olefination.
authors.affiliation: Natural Product Chemistry Division, Indian Institute of Chemical Technology, Hyderabad 500007, India. sraghavan@iict.res.in.
authors.forename: Sadagopan
authors.initials: S
authors.lastname: Raghavan
authors.forename: Sheelamanthula
authors.initials: S
authors.lastname: Rajendar
mesh_terms: D005231:Fatty Acids, Unsaturated / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D005231:Fatty Acids, Unsaturated; C421091:callystatin A