The new chemical cascade reaction was found: the direct formation of substituted 4-oxo-2,7-diaryl-5-oxa-6-azaspiro[2.4]hept-6-ene-1,1-dicarbonitriles
from benzylidenemalononitriles and 3-aryl-2-isoxazol-5(4H)-ones. The action of bromine on the equimolar mixture of benzylidenemalononitrile
and 3-aryl-2-isoxazol-5(4H)-one in the basic alcohol solution results in stereoselective formation of spirobicycle
containing the 2-isoxazolin-5-one and the cyclopropane fragments in 53–92% yields.
Thus, the new simple and efficient ‘one-pot’ approach to substituted (2R*,3R*)-4-oxo-2,7-diaryl-5-oxa-6-azaspiro[2.4]hept-6-ene-1,1-dicarbonitriles was found
directly from simple and reasonable starting compounds as benzylidenemalonitriles
and 3-aryl-2-isoxazol-5(4H)-ones.
Key words
MHIRC reaction - cyclopropane formation - 3-aryl-2-isoxazolin-5(4
H)-ones - benzylidenemalononitriles - 5-oxa-6-azaspiro[2.4]hept-6-enes