plify the calculation, interconversions involving Ms, M6, and M, were not considered. These minima have 1,2-cis-

No abstract

the spectrum of the f3( 1 +4) linked disaccharide peracetate lop, however, 3-H appears at lower field (6=5.18) and 4-H at higher field (6 = 3.87), i. e. an acetyl group is located on C-3 in the lyxo building unit, and the interglycosidic bond is different from that in the B-A part of 2. In contrast, in the p(1-3) linked, acetylated derivative 88 3-H (6 = 4.16) and 4-H (6= 5.21) show only slight deviations in the chemical shifts compared to those of the B-A fragment of 2 . Hence, in mithramycin 1 there is a p(1-3) linkage between the D-arabino-(€3) and the D-lyxo-building unit (A).

Das vollständige Manuskript dieser Zuschrift erscheint in: Angew. Chem. Suppl. 1983, 10. DOI: