Hetero Diels-Alder reaction using nitroso dienophiles

Efficient hetero Diels-Alder reactions have been carried out using a-chloronitroso saccharides as dienophiles and various symmetrical and unsymmetrical dienes. Thus, 2,3 5,6-di-0-isopropyli-dene-l-C-nitroso-a-D-mannofuranosyl chloride 122, easily prepared from hydroximolactone 121 and tert-butyIhypochlorite, was proven to be a stable and highly reactive dienophilic compound [92]. 

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