Deoxy derivatives amines

Fortimicin B has been converted to dactimicin (391) by selective formimidation of the 2"-amino group with formimidate hydrochloride in dry ethanol [225]. Another report described the synthesis of a number of fortimicin KG2 analogs, including 3,4-didemethyl, 4-demethyl, and 3-amino-4-demethoxy-4-deoxy derivatives from sis-amine [226]. 

When 1,2 3,5-di-0-isopropylidene-6-0-p-tolylsulfonyl-n-glucofuranose is heated with methanolic ammonia, three products are obtained. These were described as (a) the 6-amino-6-deoxy derivative, arising by direct displacement of the sulfonyloxy group, (b) a secondary amine containing two sugar residues, formed, presumably, from the first compound, and (c) the enolic compound, 6-deoxy-l, 2 3,5-di-0-isopropylidene-D-a 2/lo-hex-5-enose (118, R = Ri = Me).i Subsequently, this last elimination was carried... 

The L-sugar analogue 118 was prepared by C-5 inversion (sulfonate displacement) in an open chain intermediate en route to 117 (X=N3). A precursor for purpurosamine synthesis, 6-acetamido-3,4,6-trideoxy-D-glucal, was obtained in 63% e.e. by lipase-catalysed enantioselective JV-acetylation of the corresponding racemic acrolein-derived amine. Syntheses of various 4-deoxy-4-guanadino-analogues of. -acetylneuraminic acid and its 2-deoxy-2,3-unsaturated derivative, are covered in Chapter 16. 

The seco amide alkaloids have been subjected to various transformations, mainly for structure elucidation purposes. When treated with lithium aluminium hydride, arnottianamide (206) was converted to the tertiary amine, deoxyarnottianamide (224), which on methylation with the Rodionow reagent gave deoxy-O-methylarnottianamide (225) (172,175). Arnottianamide (206) could be O-acetylated (174) as well as O-methylated with diazomethane in HMPA (172). Isoarnottianamide (208) was O-methylated to trimethoxy derivative 226, which under Bischler-Napieralski conditions recyclized to the benzophenantridine alkaloid, chelilutine (227) (176) (Scheme 33). 

The most successful modifier is cinchonidine and its enantiomer cinchonine, but some work in expanding the repertoire of substrate/modifier/catalyst combinations has been reported (S)-(-)-l-(l-naphthyl)ethylamine or (//)-1 -(I -naphth T)eth Tamine for Pt/alumina [108,231], derivatives of cinchona alkaloid such as 10,11-dihydrocinchonidine [36,71], 2-phenyl-9-deoxy-10, 11-dihydrocinchonidine [55], and O-methyl-cinchonidine for Pt/alumina [133], ephedrine for Pd/alumina [107], (-)-dihydroapovincaminic acid ethyl ester (-)-DHVIN for Pd/TiOz [122], (-)-dihydrovinpocetine for Pt/alumina [42], chiral amines such as 1 -(1 -naphtln I)-2-(I -pyrro 1 idiny 1) ethanol, l-(9-anthracenyl)-2-(l-pyrrolidinyl)ethanol, l-(9-triptycenyl)-2-(l-pyrrol idi nyl)cthanol, (Z )-2-(l-pyrrolidinyl)-l-(l-naphthyl)ethanol for Pt/alumina [37,116], D- and L-histidine and methyl esters of d- and L-tryptophan for Pt/alumina [35], morphine alkaloids [113],... 

Several 2-amino-2-deoxy-D-gulononitrile derivatives (68) have been obtained by treating D-xylose with hydrogen cyanide and an amine. Among the amines that were used in preparing these derivatives were aniline,107-109 9-aminofluorene,110 p-methylphenylamine,109 and benzylamine.109 In all cases, as expected, both the D- and L-gly-cero configurations at C-2 are formed. When a solution of 68 (R = Ph)... 

Figure 8.1 Time-resolved DRIFTS spectra of the reduction of a resin-bound 2-deoxy-2-azidoglucuronic acid derivative to the corresponding amine.12...

Derivatives (Table I) formed by the reaction of the chosen polysaccharide with an isocyanate or acid chloride are carbamates and esters respectively. However, chitin or poly[(1+4)(N-acetyl-2-amino-2-deoxy-f3-glucopyranose)] actually used in this experiment contains approximately 16% free amine groups which can form urea and amide derivatives with the above reagents. 

Ross and Ugi" prepared l-amino-5-deoxy-5-thio-2,3,4-tri-6)-isobutanoyl-P-D-xylopyranose 61a from xylose via the 5-desoxy-5-thio-D-xylopyranose. The U-4CRs of this amine form a-aminoacid derivatives stereoselectively and in excellent yields. These products have the advantage that their products are stable and their auxiliary group 5-desoxy-5-thio-D-xylopyranose can be cleaved off selectively by mercury(II) acetate and trifluoroacetic acid. The expected steric structure of the corresponding U-4CR product was confirmed by X-ray measurement. 

He et al. elaborated on the concept of cinchona derivatives and produced the ligands 9-amino(9-deoxy)epiquinine (96a) and epicinchonine (96b) (Scheme 4.44) [87]. The amines were tested with both Rh and Ir precursors for the ATH of ketones in PrOH/KOH. The best results were achieved using 96b as the ligand and [lr(cod)Cl]2 as the metal precursor, and for isobutyrophenone the conversion and enantioselectivity were obtained in 90 and 97% ee, respechvely. Later it was shown that the Ir complex of 9-amino(9-deoxy)epicinchonine 96b could be recovered in high yields with dilute HCl. The yields (90-94%) and enanhoselectivities of 1-phenylethanol (93-95% ee) were maintained with small variahons after six cycles [88]. 

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