Total Synthesis of Nucleoside Antibiotics Amicetin, Plicacetin, and Cytosaminomycin A—D

Abstract

Main observation and conclusion Amicetin and congeners constitute a small family of complex pyrimidine nucleosides, which exhibit strong antibiotic activities against Gram‐positive bacteria and notably against strains of Mycobacterium tuberculosis. Herein, we report chemical synthesis of a series of disaccharide congeners of the amicetin family, including amicetin, plicacetin, and cytosaminomycin A—D. It is the first time for successful synthesis of amicetin, the prototypical member, and cytosaminomycins. The synthetic approach employs glycosyl N‐phenyltrifluoroacetimidate and thioglycoside donors to construct the characteristic aminodeoxydisaccharides consisting of α‐(1→4)‐glycosidic linkage, uses gold(I)‐catalyzed N‐glycosylation to furnish 2‐deoxy‐β‐nucleosides, and finally exploits amidation and global deprotection to complete the syntheses. It is noteworthy that the 3‐O‐protecting group in the 2‐deoxydisaccharide donors is found to be crucial for a successful N‐glycosylation to assemble the cytosaminomycin disaccharide nucleosides.

Total Synthesis of Starfish Cyclic Steroid Glycosides. Part 3, Formal Total Synthesis of Luzonicosides A and D

“…Au(I) catalyzed glycosylation with glycosyl ortho ‐alkynylbenzoates as donors is highly powerful and extremely mild, gaining widespread application in the synthesis of complex molecules. [ 23‐33 ] Thus, ortho ‐hexynylbenzoates 5 and 35 were synthesized by condensation of corresponding hemiacetals with ortho ‐ hexynylbenzoic acid in 92% and 98% yields, respectively (Scheme 5a, see Supporting Information for details). To our delight, coupling of disaccharide 33 with 5 under the action of Ph 3 PAuNTf 2 in toluene proceeded smoothly, resulting in trisaccharide 36 in an excellent 96% yield.…”

Stereoselective Synthesis and Immunological Evaluation of Common O‐antigen of P. mirabilisOE and P. vulgarisTG103

“…And the glycosylation yield can be improved to 89% by use of gold(I)‐catalyzed glycosylation with glycosyl o ‐alkynylbenzoate 27 as donor. [ 63‐64 ] Next, reduction and acetylation of nitro group and azide furnished 38 in 53% yield. Removal of silyl groups and acetylation furnished 39 in 79% over…”

Recent asymmetric synthesis of natural products bearing an α-tertiary amine moiety via temporary chirality induction strategies

“…2.2 Total synthesis from serine 2.2.1 (+)-Amicetin. In 2021, Xu and Yu reported the total synthesis of nucleoside antibiotics, including amicetin, plicacetin, and cytosaminomycin A-D. 18 Among these, (+)-amicetin (5, Scheme 2) features a p-aminobenzoyl moiety amidated with a-methyl-L-serine. Xu and Yu started the synthesis of amicetin using a-methyl-L-serine derivative 6 as a chiral starting material.…”