Diastereofacial selectivity of the cycloaddition of diazo compounds to enones
作者:G Galley、M Pätzel、P.G Jones
DOI:10.1016/0040-4020(94)01049-6
日期:1995.2
Chiral α,β-unsaturated γ-alkoxy- or γ-amino-ketones (enones) 1 react with diazocompounds in a stereoselective manner affording conjugated Δ2-pyrazolines 5 and 6. In all cases syn-selectivity for the cycloaddition was observed. The diastereomeric ratio is improved at lower temperatures, but no significant influence of high pressure is observed. Carrying out this reaction with (E) and (Z) derivatives