Published as part of the 50 Years SYNTHESIS – Golden Anniversary Issue
Abstract
The organocatalytic Michael reaction of easily available 1-cyclopentene-1-carbaldehyde
and 1,3-dicarbonyl compounds led to cyclopentanecarbaldehydes on a gram scale with
low catalyst loading (2 mol%) and high enantioselectivity. The synthetic potential
of 4-acylhexahydroindenones from intramolecular aldol condensation was demonstrated
by Diels–Alder reaction to a tetracyclic derivative with seven stereogenic centers.
The diastereofacial preference of the tetracyclic product was confirmed by DFT calculations.
The described reaction sequence is characterized by few redox-economic steps and high
degree of molecular complexity.
Key words
organocatalysis - hydrindane - Jørgensen–Hayashi catalyst - Michael addition - aldol
condensation - Diels–Alder reaction