RESUMEN
The new oxaziridinium salt 5 (R2 = TBDPS) is an effective reagent for the highly enantioselective oxidation of sulfides to sulfoxides with up to >99% ee and good yields. As such, it represents a new valuable nonmetallic alternative to the existing methods for asymmetric sulfoxidation.
Asunto(s)
Aziridinas/química , Sulfuros/química , Sulfóxidos/síntesis química , Aziridinas/síntesis química , Estructura Molecular , Oxidación-Reducción , Estereoisomerismo , Sulfóxidos/químicaRESUMEN
Four new 9R,13R-epoxylabdane diterpenes (1-4) and a known clerodane derivative, 3,4beta-epoxy-5beta,10beta-cis-17alpha, 20alpha-clerod-13(14)-en-15,16-olide, were isolated from the leaves of Stevia subpubescens. The structures, which correspond to the grindelane class of diterpenoids, were elucidated by NMR data, chemical correlation, and single-crystal X-ray diffraction analysis of monoacetate 5. The absolute configuration of 1-4 is based on the optical activity of ketone 3 as compared with data of closely related substances.
