Tetrahydropyrazolopyrazolones and a tetrahydropyrazolodiazocinone containing an α,β-unsaturated
ester moiety undergo highly diastereoselective conjugate reduction mediated by samarium
diiodide in the mixed solvent tetrahydrofuran and ethanol to give the corresponding
products as single diastereomers in moderate to good yields.
Key words
samarium diiodide - reduction - α,β-unsaturated ester - conjugate - heterocycle