Sibirosamine

Page 441. The first entry under Sibirosamine should read 3-epimer of, . 

A stereospecific total synthesis of the antibiotic sibirosamine was carried out using this methodology. In the first step, addition of methylmagnesium iodide to N-(phenylsulfonyl)-L-allothreonine afforded the a-amino methyl ketone in modest yield. This reaction afforded a diminished yield compared with N-(phenylsulfonyl)-L-threonine for some unexplained reason. A clever use of Ae L-amino acid serine sdlows for a straightforward preparation of o-amino acids such as o-dopa as is shown in Scheme 15. ... 

C-methyl-4-(methylamino)-L-mannose (sibirosamine), both similar to callipeltose, were found to be part of nucleosides isolated from cultures of Azobacter vinelandii [135] and as the saccharide moiety of sibiromycin, an antitumor antibiotic isolated from Streptosporangium sibiricum [136]. 

The N-phenylsulphonyl derivative (44) of sibirosamine (c.f. Scheme 10) has been synthesized from the L-allothreonine derivative (45) as shown in Scheme 14, involving stereospecific addition of... 

Yl-Me 4,6-Dideoxy-3-C-methyl-4-(methy-lamino)-D-mannose. Sibirosamine [35665-47-5]... 

The anti-tumour antibiotic sibiromycin has been assigned the structure (343) the component sugar, sibirosamine, is 4,6-dideoxy-3-C-methyl-4-methylamino-D-altropyranose (see Vol. 7, p. 148). 

The relative stereochemistry of sibirosamine, the branched-chain amino-sugar present in the benzodiazepinone antitumour antibiotic slblromycln, was shown to be that in the methyl N-tosyl-a-D-glyco-side (17) rather than in its C-3 epimer (18) as had been assigned previously (Vol. 7 p.l48 Vol. 9 P-134). The synthesis of these eplmers proceeded via 3-ene (19), a close analogue of a key intermediate In Dyong s synthesis of epimer (18) (Vol. 14, p.76 ... 

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