Synthesis of the indole nucleoside antibiotics neosidomycin and SF-2140: structural revision of neosidomycin

Abstract

Two structurally related indole nucleoside antibiotics, neosidomycin (5) and SF-2140 (3) have been synthesised; it is confirmed that the structure initially proposed for neosidomycin must be revised.In 1979, a novel N-glycosyl indole antibiotic, neosidomycin, was isolated from a strain of Streptomyces hygroscopicus. The relative stereostructure (1) was assigned to neosidomycin, principally on the basis of the n.m.r. data of its di-0-acetyl derivative (2), with the assumption that both (1) and (2) adopt 4c1(D) chair conformations in solution. More recently, the antiviral indole nucleoside SF-2140 has been isolated from an Actinomadura species, and, on the basis of degradative, spectroscopic, and X-ray data, assigned structure (3).2 In order to reconcile the crystallographic and 1H n.m.r. data, which included in particular large coupling constants J 1 j ,2! and J41ax,51, the authors postulated that, in solution, SF-2140 (3) and its di-0-acetyl derivative (4) adopt twist-boat conformations, as illustrated in (4') for the derivative. Since the

Synthesis of 4-Deoxy-l-(and d-)hexoses from Chiral Noncarbohydrate Building Blocks

“…Deoxy-hexoses most frequently occurring in nature are 2-deoxy-, 6-deoxy-, and 2,6-dideoxy-hexoses, whereas 3-deoxy- and 4-deoxy-hexoses are quite rare compounds. Buchanan and co-workers have recognized methyl 4-deoxy- d - lyxo -hexopyranuronate to be the sugar moiety of both neosidomycin and SF-2140, two indole nucleoside antibiotics …”

Nucleosides and Nucleotides

“…Neosidomycin (63) and SF-2140 (64) are indole N-glycosides produced by S. hygroscopicus and Actinomadura, respectively (195,196). A revised structure for (63) has appeared (197). Compound (64) contains an α-N-glycoside linkage.…”

Recent progress in the chemistry of indole alkaloids and mould metabolites

“…'' In the indoloditerpene series the /I-pyrone ketal (37a), which constitutes rings D--G of paspalicine, has been ~ynthesized,'~ and a concise route to the indole-oxocane derivative (37b), a model for the total synthesis of penitrem D, has been described.35 The synthesis of the closely related indole antibiotics neosidomycin (43), which was isolated in 1979 from Streptomyces hygroscopicus, and SF-24 10 (44), a constituent of an Actinomadura species, has been reported (Scheme 4). 42 In the case of neosidomycin this has resulted in a considerable revision of the stereochemistry of the molecule. from the same source.…”