Novel strategies for the synthesis of anthrapyran antibiotics: discovery of a new antitumor agent and total synthesis of (S)-espicufolin
作者:Lutz F. Tietze、Kersten M. Gericke、Ramakrishna Reddy Singidi、Ingrid Schuberth
DOI:10.1039/b700838d
日期:——
Two high-yielding strategies for the synthesis of 4H-anthra[1,2-b]pyran antibiotics have been developed giving access to novel antitumoragent (ED(50) 1.5 microm) and to (S)-espicufolin (3). A key step for the assembly of the tetracyclic 4H-anthra[1,2-b]pyran-4,7,12-trione skeleton is the nucleophilic addition of an aryl lithium species onto an aldehyde which allows the introduction of either an ynone
Isolation, Enantioselective Total Synthesis and Structure Determination of the Anthrapyran Metabolite SS 43405-e
作者:Lutz F. Tietze、Ramakrishna Reddy Singidi、Kersten M. Gericke、Henning Böckemeier、Hartmut Laatsch
DOI:10.1002/ejoc.200700534
日期:2007.12
The first enantioselectivetotalsynthesis of the anthrapyranmetaboliteSS43405-e, isolated from a marine-derived streptomycete, is described, which also allows the determination of the so far unknown absolute (R) configuration of the natural product. For the synthesis the bromoanthracene derivative 3 is lithiated and coupled with the enantiopure aldehyde (S)-4 to give 9, which is oxidatively transformed