Lipase mediated desymmetrization of meso-2,6-di(acetoxymethyl)-tetrahydropyran-4-one derivatives. An innovative route to enantiopure 2,4,6-trifunctionalized C-glycosides
摘要:
The desymmetrization of several meso-configurated 2,4,6-trifunctionalized tetrahydropyrans was studied. Amongst the derivatives investigated the conformationally more rigid spiro ketal 8b afforded hydroxy-acetate (-)-12 in excellent chemical yield and enantiomeric excess. The absolute configuration of the resulting 2,4,6-trifunctionalized C-glycosides was established by X-ray crystal diffraction. Copyright (C) 1996 Elsevier Science Ltd
Chelidonic Acid as Precursor for 2,5-Desoxy-C-glycosides
摘要:
Diethyl chelidonate (1) was converted by 5 convenient steps into the 2,4,6-trifunctionolized tetrahydropyran (6), which is a key intermediate for natural products and peptide turn mimetics. The important all syn-configuration was achieved by catalytic hydrogenation.