Multicomponent reaction (MCR) for constructing bis-spirocyclohexane skeletons using β-nitrostyrene derived MBH acetates, 1,3-indanedione and aldehydes via [1 + 1 + 1 + 3] annulation

An AB(2)C type four-component quadruple cascade reaction has been established between nitroallylic MBH acetate, 1,3-indanedione and aldehyde for generating bis-spirocyclohexanes. This reaction progressed in an unusual [1 + 1 + 1 + 3] annulation manner via a Knoevenagel/Michael/Michael/Michael sequence, resulting in the generation of three/four chiral centres, and two all-carbon quaternary centres through the formation of 3 new C-C bonds.