Stereoselective Synthesis of Novel Uracil Polyoxin C Conjugates as Substrate Analogues of Chitin Synthase
摘要:
Stereoselective syntheses of both the natural (C5'-S) and unnatural (C5'-R) diastereoisomers of uracil polyoxin C methyl ester have been developed. The key stereocontrolled step involves nucleophilic addition of trimethylsilyl cyanide to the appropriate chiral sulfinimine derived from 2',3'-protected 5'-formyluridine and (S)-(-)-tert-butanesulfinamide or (R)-(+)-tert-butanesulfinamide, respectively. A variety of substrate mimics designed to function as inhibitors of chitin synthase have been synthesized by conjugation of the methyl ester of uracil polyoxin C (UPOC) with activated isoxazole carboxylic acids. Amide bond formation was accomplished via coupling of the amino functionality of UPOC methyl ester with a free isoxazole acid using HBTU or alternatively an isoxazole pentafluorophenyl ester. The substrate mimics incorporate features of the nucleoside-peptide antibiotics, the polyoxins and the nikkomycins, as well as features of the transition state structure expected during polymerization of the natural chitin synthase substrate uridine diphosphoryl-N-acetylglucosamine (UDP-GlcNAc), namely, a metal-binding site and glycosyl oxocarbenium ion mimic.
Stereoselective Synthesis of Novel Uracil Polyoxin C Conjugates as Substrate Analogues of Chitin Synthase
摘要:
Stereoselective syntheses of both the natural (C5'-S) and unnatural (C5'-R) diastereoisomers of uracil polyoxin C methyl ester have been developed. The key stereocontrolled step involves nucleophilic addition of trimethylsilyl cyanide to the appropriate chiral sulfinimine derived from 2',3'-protected 5'-formyluridine and (S)-(-)-tert-butanesulfinamide or (R)-(+)-tert-butanesulfinamide, respectively. A variety of substrate mimics designed to function as inhibitors of chitin synthase have been synthesized by conjugation of the methyl ester of uracil polyoxin C (UPOC) with activated isoxazole carboxylic acids. Amide bond formation was accomplished via coupling of the amino functionality of UPOC methyl ester with a free isoxazole acid using HBTU or alternatively an isoxazole pentafluorophenyl ester. The substrate mimics incorporate features of the nucleoside-peptide antibiotics, the polyoxins and the nikkomycins, as well as features of the transition state structure expected during polymerization of the natural chitin synthase substrate uridine diphosphoryl-N-acetylglucosamine (UDP-GlcNAc), namely, a metal-binding site and glycosyl oxocarbenium ion mimic.
Application of the Ugi Reaction for the One-Pot Synthesis of Uracil Polyoxin C Analogues
作者:Andrew Plant、Peter Thompson、David M. Williams
DOI:10.1021/jo900244m
日期:2009.7.3
of uracil polyoxin C (UPOC) methyl ester using the Ugireaction is described. The four components employed in the Ugireaction are 2′,3′-isopropylidine-protected uridine-5′-aldehyde, 2,4-dimethoxybenzylamine, an isoxazolecarboxylic acid, and the convertibleisonitrile N-(2-[(tert-butyldimethylsilyl)oxy]methyl}phenyl)carbonitrile. Following the Ugireaction, treatment with HCl in MeOH achieves deprotection
Stereoselective Synthesis of Novel Uracil Polyoxin C Conjugates as Substrate Analogues of Chitin Synthase
作者:Andrew Plant、Peter Thompson、David M. Williams
DOI:10.1021/jo702564y
日期:2008.5.1
Stereoselective syntheses of both the natural (C5'-S) and unnatural (C5'-R) diastereoisomers of uracil polyoxin C methyl ester have been developed. The key stereocontrolled step involves nucleophilic addition of trimethylsilyl cyanide to the appropriate chiral sulfinimine derived from 2',3'-protected 5'-formyluridine and (S)-(-)-tert-butanesulfinamide or (R)-(+)-tert-butanesulfinamide, respectively. A variety of substrate mimics designed to function as inhibitors of chitin synthase have been synthesized by conjugation of the methyl ester of uracil polyoxin C (UPOC) with activated isoxazole carboxylic acids. Amide bond formation was accomplished via coupling of the amino functionality of UPOC methyl ester with a free isoxazole acid using HBTU or alternatively an isoxazole pentafluorophenyl ester. The substrate mimics incorporate features of the nucleoside-peptide antibiotics, the polyoxins and the nikkomycins, as well as features of the transition state structure expected during polymerization of the natural chitin synthase substrate uridine diphosphoryl-N-acetylglucosamine (UDP-GlcNAc), namely, a metal-binding site and glycosyl oxocarbenium ion mimic.