Stereoselective synthesis of (3S,5S,6S)-tetrahydro-6-isopropyl-3,5-dimethylpyran-2-one; a C5-epimer of a component of a natural sex pheromone of the wasp Macrocentrus grandii, the larval parasitoid of the European corn borer Ostrinia nubilalis
作者:Denis Shklyaruck、Evgenii Matiushenkov
DOI:10.1016/j.tetasy.2011.08.005
日期:2011.7
(3S,5S,6S)-Tetrahydro-6-isopropyl-3,5-dimethylpyran-2-one, a C5-epimer of a component of the natural sexpheromone of the wasp Macrocentrusgrandii, the larval parasitoid of the European corn borer Ostrinia nubilalis, was synthesized starting from methyl l-valinate. The transformation includes a Kulinkovich cyclopropanation reaction, a cationic cyclopropyl-allyl rearrangement of cyclopropyl methanesulfonate
Killing two birds with one stone. The ortho-diphenylphosphanylbenzoyl group (o-DPPB) acts as a catalyst-directing group in stereoselective Rh-catalyzed hydroformylation and as a reagent-directing group in stereoselective1,4-addition of Gilman cuprates to acyclic enoates (see picture on the right; the o-DPPB group is represented by a sphere, D=donor). These two reactions could be efficiently used as
o-DPPB-Directed Stereoselective Conjugate Addition of Organocuprates
作者:Bernhard Breit、Peter Demel
DOI:10.1016/s0040-4020(00)00139-3
日期:2000.4
Substrate-directed diastereoselective conjugateaddition of Gilman cuprates to acyclic enoates has been achieved with the aid of the substrate-bound reagent-directing o-DPPB-group (o-DPPB=ortho-diphenylphosphanyl benzoate). Combining o-DPPB-directed hydroformylation with the o-DPPB-directed cuprate addition provides access to building blocks with up to four stereogenic centers, which may be of relevance