Synthesis, high-resolution NMR spectroscopic analysis, and single-crystal X-ray diffraction of isoxazoline tetracycles
摘要:
Three isoxazoline tetracycles were obtained enantiomerically pure by intramolecular 1,3-dipolar cycloaddition. The characterization of the new compounds was performed by high-resolution H-1 and C-13 NMR spectroscopy. The relative configuration of the new chiral centers was determined by NOESY experiments and confirmed by single-crystal X-ray structural analysis. (C) 2002 Elsevier Science Ltd. All rights reserved.
Stereoselective Synthesis of Chiral Oxepanes and Pyrans through Intramolecular Nitrone Cycloaddition in Organized Aqueous Media
作者:Amrita Chatterjee、Pranab K. Bhattacharya
DOI:10.1021/jo051414j
日期:2006.1.1
A highly stereoselective surfactant-catalyzed intramolecularnitrone (formed by dehydration in water) cycloaddition in aqueous media leading to exclusive formation of a single isomer is reported. Either oxepane or pyran is formed from 3-O-allyl furanoside derivatives, which constitute the framework of a large number of biologically active compounds. Therefore, the environmentally friendly, efficient
The synthesis of a new furo-pyran-based isoxazolidine, making use of an intramolecular oxime-olefin cycloaddition (IOOC) reaction, is reported here, starting from diacetone glucose. (C) 1999 Elsevier Science Ltd. All rights reserved.