- The discovery and structure-activity relationships leading to CE-156811, a difluorophenyl cyclopropyl fluoroether: A novel potent antibacterial analog derived from hygromycin A
-
SAR studies and optimization of various modified Hygromycin A fluoroalkyl ethers, which led to the discovery of the highly potent 4′-(2-cyclopropyl- 2-fluoroethyl ether) antibacterial CE-156811 (1) derived from truncation of the ribose ring and difluorination of the phenyl found in Hygromycin A, are discussed.
- Le, Phuong T.,Brickner, Steven J.,Wade, Sarah K.,Brighty, Katherine,Monahan, Rhonda,Stone, Gregory G.,Girard, Dennis,Finegan, Steve,Duignan, Joan,Schafer, John,Maloney, Meghan,Zaniewski, Richard P.,Connolly, Ann G.,Liras, Jennifer,Bordner, Jon,Samardjiev, Ivan
-
scheme or table
p. 276 - 279
(2011/02/27)
-
- Hydrozirconation of alkenyloxirane derivatives: Preparation of cycloalkylmethanols
-
Cyclopentyl and cyclopropylmethanol derivatives were efficiently prepared through a chemoselective hydrozirconation reaction of (1- butenyl)oxirane and vinyloxirane with Cp2ZrHCl. However, the attemped reaction of (1-pentenyl)oxirane or (1-propenyl)oxirane failed to yield cyclohexyl or cyclobutylmethanols. The ring formation was stereospecific and proceeded with the inversion of the configuration at the reacting oxirane carbon. The origin of stereospecificity and the stereoselectivity in the formation of cyclopropylmethanols was presumed by the approach of the Schwartz reagent from the less hindered site of the stable gauche-conformer of the vinyloxirane compound in the transition state. (Cyclopropylmethyl)amine derivatives were also prepared by the treatment of vinylaziridine derivatives with Cp2ZrHCl.
- Harada, Susumu,Kowase, Noboru,Tabuchi, Nobuhito,Taguchi, Takeo,Dobashi, Yasuo,Dobashi, Akira,Hanzawa, Yuji
-
p. 753 - 766
(2007/10/03)
-
- Formation of cyclopropyl carbinols through a highly diastereoselective hydrozirconation of vinyloxirane derivatives
-
Cyclopropyl carbinol derivatives were efficiently prepared through a highly diastereoseletive hydrozirconation of vinyloxiranes and the intramolecular attack of the generated alkylzirconocene with the inversion of the configuration at the reacting oxirane carbon.
- Harada, Susumu,Kowase, Noboru,Taguchi, Takeo,Hanzawa, Yuji
-
p. 1957 - 1960
(2007/10/03)
-
- SYNTHESIS OF SOME 2'-C-ALKYL DERIVATIVES OF 9-(2-PHOSPHONOMETHOXYETHYL)ADENINE AND RELATED COMPOUNDS
-
To study the effect of β-substitution in 2'-alkyl derivatives of 9-(2-phosphonomethoxyethyl)adenine (Ia) on the antiviral activity or group specificity, these derivatives were synthesized. 9-(2-Hydroxyalkyl)adenines VIII were prepared by alkylation of adenine with suitably substituted oxiranes XIII or 2-hydroxyalkyl p-toluenesulfonates IV and VI.After protection of the adenine amino group by benzylation (compounds IX) or amidine formation (compounds X), the intermediates were alkylated with bis(2-propyl) p-toluenesulfonyloxymethanephosphonate (XI) in the presence of sodium hydride.After deprotection, the obtained phosphonate diesters XII were converted into phosphoniuc acids I by transsilylation and hydrolysis.This synthetic scheme was used for the preparation of ethyl (Ie), propyl (If), 2-propyl (Ig), 2-methylpropyl (Ih), cyclopropyl (Ii), cyclohexyl (Ij), benzyl (Ik) and phenyl (Il) derivatives.The 2'-trifluoromethyl derivative XXIIa was prepared analogously from 9-(2-hydroxy-3,3,3-trifluoropropyl)adenine (XXa), obtained by alkylation of adenine sodium salt with 2-hydroxy-3,3,3-trifluoropropyl bromide. 2,6-Diaminopurine derivative XXIIb was obtained analogously. 2'-Trimethylsilyl derivative XIXa was obtained by alkylation of adenine with 2-phosphonylmethoxy-3-(4-toluenesulfonyloxy)propyltrimethylsilane (XVII) followed by transsilylation and hydrolysis of diester XVIIIa. 9-(3-Phosphonomethoxybutyl)adenine (XXVIII) and 9-(2-methyl-2-phosphonomethoxypropyl)adenine (XXXV) were prepared from the corresponding hydroxy derivatives XXVIb and XXXII, respectively, by the same reaction pathway as derivatives I.
- Cvorakova, Hana,Holy, Antonin,Rosenberg, Ivan
-
p. 2069 - 2094
(2007/10/02)
-