Stereoisomers of 4-amino-3-hydroxy-1-cyclohexanecarboxylic acid and 4-amino-3-oxo-1-cyclohexanecarboxylic acid as mimetics of a twisted cis-amide bond
摘要:
Stereoselective synthesis of the title compounds was performed. The relative configuration of methyl t-4-(tert-butoxycarbonylamino)-c-3-hydroxy-r-1-cyclohexanecarboxylate and methyl trans-4-(tert-butoxycarbonylamino)-3-oxo-r-1-cyclohexanecarboxylate was confirmed by X-ray diffraction methods. Analogues of cyclolinopeptide A (CLA) containing these twisted cis-amide bond mimetics were then synthesised. (C) 2001 Elsevier Science Ltd. All rights reserved.
reported for the conversion of alkenes to 1,2-dibromo alkanes via oxidative bromination using HBr paired with dimethylsulfoxide, which serves as the oxidant as well as cosolvent. The substrate scope includes 21 olefins brominated in good to excellent yields. Three of six styrene derivatives yielded bromohydrins under the reaction conditions.