Diastereoselective syntheses of α-amino-β-hydroxyesters precursors of the ribosyl-diazepanone core of the liposidomycins

Synthetic route towards (5R,2′S,5′S,6′S)-ribosyl-diazepanone, an analogue core of the liposidomycins

“…The catalyst, prepared in situ from commercially available Ru(Cod)(2-methylallyl) 2 , 9 was shown to control the stereochemistry at the created hydroxyl centre. 10 Electrophilic amination of the zinc enolate of 6 was performed at À78°C with dibenzyl azodicarboxylate to produce anti-diastereoisomer 7 in 56% yield and with complete diastereoselectivity. Catalytic hydrogenolysis of the benzyl carbamates and of the N-N bond under atmospheric pressure occurred simultaneously in the presence of Raney Ni.…”

“…Crystallographic analysis of a tert-butyldimethylsilyl ether derivative of 8 shows an anti-relationship between the two adjacent aminated and hydroxylated carbons with C-5 (R) and C-6 (S) absolute configurations. 10 Protection of the hydroxyl function of 8 with a methoxyethoxymethyl group followed by hydrogenolysis of the benzhydryl group in ethanol with Pd/C as catalyst gave a-ribosylamino ester 2 in 58% yield (Scheme 2).…”

Fine Synthetic Nucleoside Chemistry Based on Nucleoside Natural Products Synthesis

“…More than 8 groups have studied the total synthesis of LPMs. [123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140] Difficulty in the synthesis of this class of molecules may lie with the introduction of 5-aminoribose moiety found in CPZs and LPMs after construction of a uridyldiazepanone moiety because the tertiary amine contained in the diazepanone structure inhibited the usual ribosylation promoted by Lewis acid. In addition, CPZs and LPMs would be sensitive to basic conditions because they contain a b-heterosubstituted carboxyl moiety.…”

Chemistry and Biod iversity of the Biologically Active Natural Glycosides

“…Thus, methymycin (466), neomethymycin (467), and YC-17 (468) were detected in culture broths of a Streptomyces species [273 ± 275]. Synthesis of methymycin (466) has been reported [276].…”

“…They inhibit the formation of the lipidintermediate in bacterial peptidoglycan synthesis [467]. Diastereoselective synthesis of the liposidomycins was reported [468].…”