Synthesis from D-glucosamine

2-acetyl derivative could be obtained by acetylation or directly in a single step from N-acetyl-D-mannosamine by oxidation with Br2. Selective oxidative cleavage of C-5-C-6 bond in the acetyl derivative of 5 with aqueous NaI04 afforded the aldehyde 6 in quantitative yield, which may exist in equilibrium with the dimer 7. Dissolution of 6 in NH4OAC and heating in the presence of Cu(OAc)2 and excess formaldehyde afforded Cu(II) complex of A-acetyl-DL-eryr/ ro-(3-hydroxyhistidine (8) in 25% yield, whose deacetylation gave 9. 

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Synthesis from D-glucosamine 2S,5S-Dihydroxymethyl-37 ,47 -dihydroxypyrro-lidine (23) was synthesized from D-glucosamine via compound 21 (Scheme 3). ° Treatment of 21 with DMP followed by tosylation produced the tosylate 22, which was cyclized with NaOEt to afford the imino sugar 23. 

However, it should be noted that the concept of carbohydrates as chiral synthons has always fascinated sugar chemists as the excellent 1972 review by Inch will attest 42). Thus in order to preserve historical perspective three antecedents for the use of sugars in asymmetric syntheses are noted in Scheme 1. First is Wolfrom s proof of the structure of (-t-)-alanine by synthesis from D-glucosamine 102). Second is the synthesis of the optically pure mandelic acid derivatives from 2,3-4,5-di-O-isopropylidene-fl/tfeAy o-D-arabinose (1) by Bonner (9), and third is Lemieux s synthesis of ethanol-l-d from diacetone glucose (6 a, Scheme 2) via the deuterated xylose (2) (57). 

Pezzotti, F., Therisod, H. and Therisod, M., Enz3Tnatic synthesis of D-glucosaminic acid from D-glucosamine. Carbohydr. Res., 2005, 340, 139. 

The first recorded use of carbohydrates as templates for the synthesis of the sphingosine bases was for the preparation of A-benzoylphytosphingosine (6) [34, 35]. The oxazoline derivative (1) which is readily prepared from D-glucosamine [36] was con-... 

Murakami, T. Minamikawa, H. Hato, M. Regio- and stereocontrolled synthesis of D-erytbrosphingosine and phytosphingosine from D-glucosamine. Tetrahedron Lett. 1994,... 

Attempts to extend this work to the keto-oxime substrate 54 derived from D-glucosamine with an JV-phthalimido group resulted in the formation of a completely different product (Scheme 40). In this case, cyclization was initiated by reduction of the phthalimido carbonyl group to its corresponding ketyl radical anion followed by cyclization onto the ketone, providing an a-hydroxylactam 55 which was proposed to be a potentially useful scaffold for diversity-oriented synthesis. 

One of the earliest syntheses of a chiral compound from a carbohydrate was reported by Wolfrom, Lemieux and Olin, who described the preparation of optically active L-alanine from D-glucosamine [17]. This transformation was devised to establish the strucmre of alanine from the known D-glucosamine. Only a few functional group manipulations were needed in this synthesis, such as elaboration of the aldehyde group into the methyl group of alanine through the corresponding dithioacetal. Excision of three carbon atoms was also required (Scheme 11.1). 

Synthesis from o-glucosamine Aziridino[l,2-a]pyrrolidine (26), a substructure of azinomycins A and B, has been synthesized from D-glucosamine (Scheme 3)f The p-methoxybenzylidene acetal 19, 3-65 fj-Qjjj o-glucosamine in overall yield 40-50%,... 

Synthesis from o-glucosamine The p-amino acid 63, derived from D-glucosamine, was used for the synthesis of p-nitrobenzyl ester of carbapenem SQ 27860... 

Synthesis from o-glucosamine The first asymmetric syntheses of (-)-rosmari-necine (20) and (-)-7-deoxyrosmarinecine (118) have been carried out using the carbamate 108, " prepared from methyl a-D-glucosaminide (Schemes 6 and 7). ° Silylation of 108 with TBSCl followed by condensation with allylmagnesium bromide afforded the threo isomer 109. The R configuration of the newly formed asymmetric carbon atom was rationalized by a chelation-controlled approach. - Oxidation of the olefin 109 with sodium... 

S.3.3.2 Synthesis from o-glucosamine Allosamizoline (8) has also been synthesized from D-glucosamine (Scheme 3). Methyl 2-amino-4,6-0-benzylidene-3-0-benzyl-2-deoxy-a-D-glucopyranoside" (26), obtained from D-glucosamine hydrochloride (25), was converted into the corresponding M,A -dimethylurea derivative, which underwent hydrolysis with aqueous acetic acid to give the diol 27 (91%). Selective iodination of the primary position and subsequent protection of the secondary hydroxyl group with... 

Barton DHR, Gero SD, Augy S, Quielet-Sire B (1986) Synthesis of carbocyclic analogs of D-glucosamine and L-idosamine from D-glucosamine. J Chem Soc Chem Commim 1399-1401... 

In the synthesis of N-acetyl-muramyl-peptides, and obviously of MDP, the most frequently used protected muramyl derivative is 1-O-benzyl-4,6-O-benzylidene-N-acetyl-muramic acid. This allows the mild and possibly simultaneous elimination of the benzylidene group and the benzyl group. Starting from D-glucosamine, either a- or p-benzyl-4,6-0-benzylidene-N-acetyl-muramide can be obtained (Fig. 4) 17, 25, 53). In spite of its slower hydrogenolysis rate 44), the a-isomer which is easier to prepare is generally preferred (55, 44) to the p-isomer 50). 

Of significance are D-glucosamine and D-mannosamine (Fig. 29). d-G1ucos-amine-6-phosphate is formed from fructose-6-phosphate by the pathway given in Fig. 32. It is subsequently transformed to iV-acetylglucosamine-6-phosphate and iV-acetylmuramic acid. Synthesis of D-glucosamine-6-phosphate includes an intramolecular oxidoreduction at positions 1 and 2 transforming the ketose to an aldose derivative. 

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