Total Synthesis of 4′′‐O‐Acetylmananthoside B Part II: Synthesis of the Disaccharide Fragment

Abstract

(17), was successfully synthesized from two monosaccharides L-arabinose and D-galactose and fully characterized. This compound can be used to build a natural product 4''-O-acetylmanan thoside B, which was isolated from the leaves and stems of a kind of Vietnamese Acanthaceae Justicia patentiflora.

Influence of 4′-O-Glycoside Constitution and Configuration on Ribosomal Selectivity of Paromomycin

“…Glycosides 11 – 18 were prepared by glycosylation of the selectively protected paromomycin derivative 19 , with donors 20 – 28 , followed by deprotection of the immediate glycosylation products 29 – 37 , as summarized in Scheme and in Table . Thioglycosides 20 , 22 , 23 , 26 , and 27 were accessed by the literature methods, while thioglycoside 21 was prepared analogously to its enantiomer 20 . Similarly, the trichloroacetimidates 24 and 28 were obtained according to the literature methods or by minor modifications thereof.…”

First Total Synthesis of the Bioactive Arylnaphthyl Lignan 4‐O‐Glycosides Phyllanthusmin D and 4′′‐O‐Acetylmananthoside B

“…This greatly facilitates the investigation of structure–activity relationships. Nevertheless, the total synthesis of 1 and 2 has yet to be achieved, although work towards the synthesis of 2 has been reported by Wang and co‐workers . The outstanding cytotoxic selectivity of both 1 and 2 and their new mechanisms of action make them fascinating compounds.…”

Polyphosphoric Acid–Mediated, One-Pot, Novel Reactions to Build Polymethoxyarylnaphthalene Lignans

“…[5] However, because of their nonconventional structures and the presence of a number of sterically congested, strongly electron-donating groups in one molecule, such as methoxy groups and=or methylenedioxy groups, the synthesis of polymethoxyarylnaphthalene lignans and their methylenedioxy counterparts were considerably challenging. [1][2][3][4][5][6][7][8][9] During the total synthesis of 4 00 -O-acetylmananthoside B, [10][11][12][13] unexpectedly we found a polyphosphoric acid-mediated novel reaction of succinic anhydride 3 with 1,2-dimethoxybenzene 4 to produce two polymethoxyarylnaphthalene lignans, polymethoxyarylnaphthol 1 as the minor product and polymethoxynaphtho [1,2-b]oxacycloheptatrienone 2 as the major product (Scheme 1). An optimized reaction of 3 with 4 could provide 2 specifically in good yield (Scheme 2).…”

“…3H each) 13. C NMR (CDCl 3 , 75 MHz): d 149.83, 149.81, 148.87, 148.63, 148.02, 133.97, 131.75, 128.77, 125.19, 122.12, 119.79, 113.34, 111.18, 107.03, 105.01, 100.97, 55.95, 55.71.…”

“…ESI-MS, m=z ¼ 341.4 ([M þ H] þ ), 358.4 ([M þ NH 4 ] þ ), 698.6 ([2 M þ NH 4 ] þ ), 703.5 ([2 M þ Na] þ ). 2H) 13. C NMR (DMSO-d 6 , 100 MHz): d 168.93, 150.34, 149.87, 148.92, 148.60, 148.48, 148.27, 144.50, 141.33, 134.34, 131.87, 131.57, 127.43, 125.46, 122.23, 121.54, 121.41, 121.00, 119.20, 113.07, 112.01, 111.85, 111.60, 104.87, 101.46, 55.52, 55.48, 55.44, 55.31, 34.44.…”