A Tandem Aldol Condensation/Diels‐Alder Sequence of Reactions for One‐Pot Synthesis of a New Series of Polysubstituted‐Decalines

Abstract

AbstractA tandem aldol condensation/Diels‐Alder sequence of reactions was designed leading to the synthesis of a new series of derivatives of polysubstituted‐decalines. Both steps of the process took place in the same pot and in the presence of H2O/PEG as the medium and diethylamine as the catalyst of the process. The required dienes were formed in situ and reacted with the dienophile (acrylonitrile) to produce high yields of the final decaline derivatives. Mechanistic studies suggested that the process goes through an initial aldol condensation reaction followed by a [4+2] cycloaddition step and then an olefinic bond rearrangement to give the final adducts. To support the proposed mechanism, the intermediate dienes were synthesized separately as well and their stepwise reactions with the dienophile led to the same products. Ten derivatives of the target structure were prepared and then characterized by various spectroscopic methods and X‐ray crystallography analysis. The procedure was also developed to engage some other dienophiles successfully.