Trisubstituted cyclohexene carbaldehydes

The fact that the residues R -R3 of the precursors A, B and C can be broadly varied demonstrates the high flexibility of our approach. R1 of component A can bear simple to demanding residues as well as valuable functional groups (Scheme 17). R2 is limited to aromatic and heteroaromatic substituents, due to the lower reactivity of the aliphatic ni-troalkenes. The residue R3 of component C allows the broadest diversity. Aliphatic as well as aromatic moieties are tolerated. Furthermore, acrolein (R3 = H) can be used, affording trisubstituted cyclohexene carbaldehydes. The best yields were obtained with aromatic substituents R2 and R3 (38%-60%). The replacement of R3 by aliphatic residues led to lower yields (25% and 29%), whereas sterically demanding aldehydes A had less influence on the yield. In contrast, the variation of the residues had only a small impact on the diastereoselectivity (68 32-... 

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