We have devised an expeditious. efficient, asymmetric synthesis of the C(33)-C(37) fragment of amphotericin B that proceeds in 14 steps and 16% overall yield from tiglic aldehyde ((E)-2-methylbut-2-enal) with complete stereocontrol. The route described herein relies on the application of recently developed methods in catalytic asymmetric synthesis for stereocontrol through enantio- and diastereoselective functionalization of a substituted sorbate derivative.
Stereocontrolled Synthesis of the C21–C38 Fragment of the Unnatural Enantiomer of the Antibiotic Nystatin A1
作者:Thilo Berkenbusch、Reinhard Brückner
DOI:10.1002/chem.200305540
日期:2004.3.19
The C(21)-C(38) fragment all-trans-41 of the unnaturalenantiomer 1 of nystatin A(1) was prepared starting from the N-propionyl oxazolidinone 9. Aldol adduct ent-8 (ee > 96 %) derived in two steps was hydroborated with (thexyl)BH(2). Oxidative work-up and treatment with acid furnished delta-lactone 4. It contains the complete stereotetrade of the target molecule. The alpha,beta-unsaturated ester 28