Kc. Nicolaou et al., SYNTHETIC STUDIES ON MADUROPEPTIN CHROMOPHORE .2. SYNTHESIS OF THE MADUROSAMINE ARYL AMIDE AND THE C1'-C9' FRAGMENTS, Tetrahedron letters, 38(21), 1997, pp. 3671-3674
A retrosynthetic analysis (Scheme I) of maduropeptin chromophore artif
act I defined compounds 2 and 3 as required building block;. The const
ruction of 2 was achieved starling from the 2,5-dimethyl derived aroma
tic acid 8 and the D-serine derived delta-lactone 12 (Scheme 2), where
as the synthesis of 3 utilized an Evans's aldol condensation reaction
between aldehyde 13 and chiral auxiliary 14 (Scheme 3). (C) 1997 Elsev
ier Science Ltd.