Reagent-Controlled Synthesis of the Branched Trisaccharide Fragment of the Antibiotic Saccharomicin B

Abstract

A concise synthesis of a branched trisaccharide, α-l-Dig-(1 → 3)-[α-l-Eva-(1 → 4)]-β-d-Fuc, corresponding to saccharomicin B, has been developed via reagent-controlled α-selective glycosylations. Starting from the d-fucose acceptor, l- epi-vancosamine was selectively installed using 2,3-bis(2,3,4-trimethoxyphenyl)cyclopropene-1-thione/oxalyl bromide mediated dehydrative glycosylation. Following deprotection, l-digitoxose was installed using the AgPF/TTBP thioether-activation method to produce the trisaccharide as a single α-anomer. This highly functionalized trisaccharide can potentially serve as both a donor and an acceptor for the total synthesis of the antibiotic saccharomicin B.

Dissection of the Glycosylation in the Biosynthesis of the Heptadecaglycoside Antibiotic Saccharomicin A

“…SA-A and SA-B display potent activities against Gram-positive bacteria and are also active (albeit with decreased activities) against Gram-negative bacteria . Despite extensive efforts, − total synthesis of these two heptadecaglycosides has not been achieved thus far.…”

PdCl2/CuCl2/Bi(OTf)3‐promoted Construction of Sulfonyl Dibenzooxabicyclo[3.3.1]nonanes and Arylnaphthalenes via Intramolecular Annulation of Sulfonyl o‐Allylarylchromanones

“…Among these diverse kinds of reaction routes, a number of synthetic efforts have attempted to control one factor or variant to generate different products with approximate or distinct skeletons in recent reports. These adjusting factors included temperature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] catalyst, [15][16][17][18][19][20][21] additive (e. g. ligand, [22][23][24][25] base [26][27] and reagent [28][29][30][31] ) and solvent. [32][33][34][35] On the basis of the abovementioned investigations, we found that controlling the temperature change is a simple, economical and direct protocol for affecting the formation of different products in comparison with other variables.…”

Microwave‐Assisted Synthesis of Antimicrobial Agents Containing Carbazole and Thiazole Moieties

“…Recently, a series of carbazole aminothiazoles were synthesized and showed potent antimicrobial activity [31]. In view of these facts and as a part of our enduring studies in the area of antimicrobial agents [32][33][34][35][36][37][38][39], we are interested in this article to synthesize biologically active hybrid pharmacophores (carbazole and thiazole) by integrating them in one molecular platform for biological evaluation.…”