Metal-Catalyzed Cyclization of β- and γ-Allenols Derived from D-Glyceraldehyde-Synthesis of Enantiopure Dihydropyrans and Tetrahydrooxepines: An Experimental and Theoretical Study
作者:Benito Alcaide、Pedro Almendros、Teresa Martínez del Campo、Elena Soriano、José L. Marco-Contelles
DOI:10.1002/chem.200901180
日期:2009.9.14
Regiocontrolled metal‐catalyzed preparations of enantiopuredihydropyrans and tetrahydrooxepines have been synthesized starting from β‐ and γ‐allenols derivedfrom D‐glyceraldehyde. The PdII‐catalyzed cyclizative coupling reactions of β‐allenols 1 a and 1 b with allyl bromide effectively afforded enantiopure tetrafunctionalized dihydropyrans through a 6‐endo oxycyclization protocol, whereas the gold‐