Synthesis of unsaturated lactone moieties by asymmetric hetero Diels–Alder reactions with binaphthol-titanium complexes
摘要:
Natural products like ratjadone and callystatin A contain an alpha,beta -unsaturated lactone moiety which adds to the biological activity of these compounds. Here we report a rapid and practical access to lactone precursor 3 by an asymmetric hetero Diels-Alder reaction as the key step and its subsequent transformation into a suitable building block 4. (C) 2001 Elsevier Science Ltd. All rights reserved.