A selective acidic system for partial deacetylation of phenolic d-glucopyranosides per-acetates has been developed that allows synthesis of the corresponding 2'-O-acetyl-D-glucosides. Many disadvantages of generally used methods for preparing such mono-acyl derivatives involving multistep procedures or the use of enzymes are avoided. The ion at m/z 289 in mass spectra of their TMS derivatives indicates a particular and characteristic fragmentation pattern of these 2'-O-acetyl derivatives of d-glucopyranosides.
View Article and Find Full Text PDFA surprisingly selective, non-enzymatic kinetic resolution of readily available, racemic β-chiral ketones enabled the title process, which was applied to a rapid synthesis of several bioactive flavanones in virtually enantiopure form (see scheme; MOM=methoxymethyl, Ts=p-toluenesulfonyl).
View Article and Find Full Text PDFVinylsulfonamides with a furan, carbocyclic, semicyclic or acyclic 1,3-diene moiety are synthetized via a domino elimination-amidation reaction of 2-chloroethanesulfonyl chloride. Intramolecular Diels-Alder reaction of these vinylsulfonamides with thermal (toluene, 110 degrees C) or high pressure (dichloromethane, 13 kbar) activation provides efficient access to a range of gamma- and delta-sultams following a 2-3 d long synthetic procedure. Enantiopure sultams are readily obtained from N-1-phenylethyl substituted vinylsulfonamides.
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