1-Substituted morpholino ethenes—III: Carbocyclic and aliphatic heterocyclic compounds from 5-membered ring derivatives

[4+2] Cycloaddition reaction of 1-(cyclopenten-1-y1)-1-morpholino ethene with β-nitrostyrene leads to tetrahydroindan and tetrahydroindanone derivatives. A [4+2] adduct of interest is also obtained in the reaction of the same substrate with mesyl chloride. Reactivity of the same electrophiles with the morpholino enamine of cyclopentyl-methyl ketone is also examined. Some stereochemical aspects of the above mentioned reactions are discussed.