Z-2-phenyl-4-[(S)-2,2-dimethyl-1,3-dioxolan-4-ylmethylen]-5(4H)-oxazolone as the dienophile in asymmetric diels-alder reactions. II
摘要:
Diels-Alder reaction of Z-2-phenyl-4-[(S)-2,2-dimethyl-1,3-dioxolan -4-ylmethylen]-5(4H)-oxazolone and Danishefsky's diene is studied. Thermally induced reaction took place at room temperature with a high diastereofacial selectivity and Diels-Alder adducts, obtained in very high diastereomeric purity, were easily transformed into valuable compounds. The stereochemistry of the adducts has been elucidated by single crystal X-ray structure determinations, H-1-NMR analysis and mechanistic considerations. Copyright (C) 1996 Elsevier Science Ltd
Synthesis of constrained prolines by Diels–Alder reaction using a chiral unsaturated oxazolone derived from (R)-glyceraldehyde as starting material
作者:Elena Buñuel、Ana M Gil、Marı́a D Dı́az-de-Villegas、Carlos Cativiela
DOI:10.1016/s0040-4020(01)00533-6
日期:2001.7
This report describes a new route for the asymmetric synthesis of enantiomericallypure 2-substituted 7-azabicyclo[2.2.1]heptane-1-carboxylic acids, which are new conformationallyconstrained β-functionalised proline analogues. Our strategy is based on the preparation of a valuable azabicyclic intermediate by a key step that involves the intramolecular cyclisation of a derivative obtained from the