Amino cyclitols

In a related contribution O Brien described the AA on styrenes and converted the amino alcohols into enantiopure diamines by using a reaction strategy similar to Janda s [83], Further synthetic applications of the AA include a new access to Evans chiral oxazolidinones [84], the enantioselective synthesis of a-amino ketones from silyl enol ethers [85], the stereoselective synthesis of cyclohexyl norstatine [86], and a route towards amino cyclitols by aminohydroxy-lation of dienylsilanes [87]. 

Fabris F, Collins J et al (2009) Investigation of steric and functionality limits in the enzymatic dihydroxylation of benzoate esters. Versatile intermediates for the synthesis of pseudo-sugars, amino cyclitols, and bicyclic ring systems. Org Biomol Chem 7 2619-2627... 

Aldol-type cyclization of dialdehydes with nitroalkanes is a valuatde syndietic loute to amino sugars, amino cyclitols and nucleosides of amino sugars. Recently, die cyclization of die di- and tetra- de-hydes derived from sucrose (15) with nitroalkanes has appeared. It is notewordiy that the oxidadve cleavage of sucrose with LTA affords the dialdehyde selectively (Scheme 8). ... 

The aminoglycosides all contain amino sugars with the exception of spectinomycin which is more appropriately called an aminocyclitol antibiotic. All the remaining aminoglycosides contain both amino sugar and amino cyclitol moieties. Two important sub-classes exist within the... 

In 1966, Umezawa, in conjunction with Tsuchiya and Tatsuta, discovered the TACu reagent " for deteniiining configuration in aminoglycosides and amino-cyclitols. The reagent specifically fonns a copper(II) chelate between vicinal,... 

Treatment of 83 with OsOq followed by conventional decyclohexylidenation, deisopropy-lidenation and acetylation gave two branched amino cyclitols 89 (49%) and 90 (51 %), which... 

Cyclization of 5,6-dideoxv-6-nitro-D-xylo-hexofuranose led to a mixture of myo- and epi-isomers (43) which were separated and converted to the corresponding amino compounds.Examples of the use of the Ferrier reaction for preparing cyclitols and amino-cyclitols from D-glucose and D-glucosamine have been published, e.g., (44)- (45).52... 

All three components are unusual the amino sugar is based on L-glucose streptose is a branched-chain monosaccharide and streptidine is not a sugar at all, but a cyclohexane derivative called an amino cyclitol. 

Other members of this family are antibiotics called kanamycins, neomycins, and gentamicins (not shown). All are based on an amino cyclitol linked to one or more amino sugars. The glycosidic linkage is nearly always a. These antibiotics are especially useful against bacteria that are resistant to penicillins. 

The di(benzyloxy)cyclohexene (9) mentioned above has also been used to synthesize racemic deoxyinosamine, deoxyinosadiamine, and inosamine derivatives via the unsaturated inosamine derivatives (16) and (17) Scheme 5 illustrates the basic sequences that were applied to both isomers. The same group has similarly prepared racemic amino-cyclitols from 3-benzyloxycyclohexene, and 3-methoxycyclohexene was used for a synthesis of the peracety-late d DL - 2,5 - diamino -2,3,5- trideoxy-4 -0-5-N- dimethyl - ch iro - inositol (18). Base-catalysed cyclization of the substituted diones (19) gave the corresponding cyclitols (20), which were then used to prepare other 2,l -substituted cyclitols including mono- and di-amino-cyclitols, e.g., (21). ... 

Neomycin, produced by the bacterium Streptomyces fradiae, is an aminoglycoside antibiotic that shows good activity against gramnegative bacteria and some gram-positives. Neomycin is made up of neomycin B and neomycin C. Hydrolysis of neomysin B yields neamine made up of neosamine B and the amino-cyclitol, 2-deoxystreptamine, and the disaccharide neobiosamine B composed of o-ribose and neosamine B. Hydrolysis of neomycin C produces neamine and neobiosamine C, a disaccharide... 

Reviews have appeared on the synthesis of aminoglycoside antibiotics, and on the formation of new aminocyclitol antibiotics by mutants of amino-cyclitol-producing organisms fed with aminocyclohexanol or related subunits. The structures of eight minor components of the nebramycin complex elaborated by Streptomyces tenebrarius have been elucidated besides neamine and related pseudo-disaccharides, the new components are pseudo-trisaccharides related to kanamycin B, and the 3 -hydroxy analogue of the principal component of the complex, apramycin (see Vol. 10, p. 130). ... 

The preparation of amino cyclitols as building blocks for carba-oligosaccharides related to cell-surface glycans from intermediate 90 has been described." ... 

The total synthesis of the alkaloid (+)-lycoricidine from amino cyclitol 91, prepared from bromobenzene by microbial oxidation has been reported." ... 

The synthesis of amino-cyclitols related to Hygromycin A are covered in Chapter 19. 

Treatment of the epoxide 98 with TMSCN led unexpectedly to compound 99. Epoxidation of cyclopentadiene yields a di-epoxide which on treatment with sodium azide gives a mixture of products from which cyclitol 100 can be obtained as a useful precursor to carbocyclic nucleosides and amino cyclitols. 

A series of analogues of hygromycin A have been prepared by varying the acyl unit on the amino-cyclitol moiety, e.g., 40, and varying the substitution pattern or stereochemistry in the aminocyclitol ring. Although 40 was active, most variations destroyed biological activity. ... 

The S-membered amino cyclitol (61) could be prepared by radical induced cyclization of bromoxime (60). In a similar way the 6-membered cyclitols (62) and (63) were prepared. ... 

Two constituent components of the amino cyclitol antibiotics hygromycin B and destomycin A, ie. (+)-(68) and (-)-(69), known as hyosamine have been synthesized from the common precursor (67), which is readily accessible from D-mannose. ... 

Many and varied syntheses of aminoglycoside and nucleoside antibiotics and their analogues are reported in Chapters 20 and 21. Careful labelling studies over the past year or so, particularly by Rinehart s group, have provided information on the biosynthetic pathways that convert o-glucose into the amino-cyclitol moieties of streptomycin and spectinomycin (Chapter 20). 

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