[EN] NOVEL PSYMBERIN DERIVATIVES, COMPOSITIONS, AND THEIR USE AS ANTINEOPLASTIC AGENTS [FR] NOUVEAUX DÉRIVÉS ET COMPOSITIONS DE PSYMBÉRINE ET LEUR UTILISATION EN TANT QU'AGENTS ANTINÉOPLASIQUES
Synthesis of (+)-(R)-5-hydroxy-6-hydroxymethyl-7-methoxy-8-methylflavanone
摘要:
The synthesis of (+)-(R)-5-hydroxy-6-hydroxymethyl-7-methoxy-8-methylflavanone is described. A new chromylation method of beta-ketosulfoxide 9 leading to the Michael acceptor 12 has been developed. Dilithium tetrachlorocuprate was shown to be a very efficient catalyst for the conjugate addition reaction of phenyl magnesium bromide to the alpha,beta-unsaturated sulfoxide 12. The instability of the obtained adducts 10 represents a limitation in terms of yield. It was confirmed that the natural flavanone leridol does not possess the structure of title compound 1. (C) 1999 Elsevier Science Ltd. All rights reserved.
The totalsynthesis of a new member of the pederin family of natural products, psymberin 1, was accomplished. Using a recently reported novel and efficient PhI(OAc)2 mediated oxidative entry to 2-(N-acylaminal)-substituted tetrahydropyrans as the key step, this totalsynthesis was executed in a convergent and efficient manner. The longest linear sequence of this synthesis was 22 steps starting from