Penta N-

Unsymmetrically substituted tetra- and penta-n-butyl borazines are obtained by thermal decomposition of dibutylazidoborane 100> with the elimination of butene. Because of the hazards of handling boron azides, this method cannot be recommended. 

Acefia, J.L. et al. A Stereodivergent Access to Naturally Occurring Aminocarbasugars from (Phenylsulfonyl)-7-oxabicy-clo[2.2.1]heptane Derivatives. Total Synthesis of Penta-N.O-acetyl-(i-)-validamine and Its Ci and C2 Stereoisomers. 3.4.1 1994 [101]... 

These results show that structures and dynamics of the penta n-alkylpentastibolanes are closely related to those of (MeAs)j and other pentaarsolanes. 

In the calix[5]arenes it is not yet known whether the p-H compound can engage in upper rim through the annulus conformational inversion, but it seems quite certain that the p-tert-buty compound cannot do so at temperatures ordinarily encountered in laboratory procedures. As anticipated, larger OR groups are necessary to curtail conformational interconversion of calix[5]arenes than for the calix[4]arenes it has been determined that the threshold size requires a group slightly more bulky than n-butyl (AG of penta-n-butyl ether of 51-Bu jYioP for ethers and n-butanoyl (AG for penta-n-butanoate of... 

The synthesis of 3, 6"-dideoxykanamydn B175, identical with 6 -deoxytob-ramycin, is achieved by conversion of penta-N-acetylkanamydn B into the 3, 6"-diiodokanamydn B and reduction... 

Deoxygentamiciii C, 224 is obtained by reduction of penta-N-benzyloxycar-bonyl-tri-O-acetyfeentamidn C with sodium in liquid ammonia Compound 224 is inactive. Gentamicin Cj and gentamine C are isolated as by-products. 

P. J. L. Daniels et synthesised 2 -epi-gentamicin Ci 225 and 2"-deoxy-gentamicin C2 226. Penta-N-acetylgentamicin Cj is mesylated at the 2 -hydroxyl group. Through solvolysis of the mesylate by participation of the vicinal trans acet-amido group, epimerisation at the 2"-C atom takes place. 

The synthesis of 6 -amino-6 -deoxygentamicin A 248 from gentamicin A 43 demonstrates of the influence of the 6 -amino group " to provide an increase in activity. 248 is synthesised by 0-acetylation of 6 -trityl-penta-N-benzyloxycarbonyl-gentamicin A, detritylation and conversion of the 6 -hydroxyl group via the tosylate and the azido compound into the 6 -hydroxyI group via the tosylate and the azido compound into the 6 -amino derivative. 

Mercaptolysis of the penta-N-acetylgentamidns C gave N,N -diacetyl-deoxystreptamine and the diethyl dithioacetal derivative of N,N -diacetyl-... 

Methyl garosaminide was isolated from the methanolyzate of sisomicin. Mercaptolysis of penta-N-acetylsisomicin gave 1,3-di-N-acetyl-2-deoxystreptamine and a diethyl dithioacetal (43) containing a ketone... 

The structure, lividomycin 5"-phosphate, was furthermore proved by chemical synthesis. Penta-N-(benzyloxycarbonyl) lividomycin A was prepared from lividomycin A by the usual Schotten-Baumann procedure in a yield of 95% it had m.p. 135-150° (dec.). Acetonation with 2,2-dimethoxypropane in N,N-dimethylformamide in the presence of p-toluenesulfonic acid at 110° for 4 hours afforded the tri-O-isopropylidene derivative of N-(benzyloxycarbonyl)lividomycin A in 49% yield m.p. 129-133° (dec.). Phosphorylation of the sole primary hydroxyl group in the D-ribose moiety of -(benzyloxycarbonyl) lividomycin A with diphenyl phosphorochloridate in dry pyridine gave penta-N-(benzyloxy-... 

Matovu, J.B., Penta, N.K., Peddeti, S., Babu, S.V., 2011. Chemical mechanical polishing of Ge in hydrogen peroxide-based sihca slurries role of ionic strength. J. Electrochem. Soc. 158 (11), H1152-H1160. 

Penta, N.K., Amanapu, H.P., Peethala, B.C., Babu, S.V., 2013a. Use of anionic surfactants for selective polishing of silicon dioxide over silicon nitride films using colloidal silica-based slurries. Appl. Surf. Sci. 283, 986—992. 

Dandu, P.R.V., Penta, N.K., Babu, S.V., 2010d. Novel alpha-amine-functionalized silica-based dispersions for selectively pohshing poly silicon and Si(lOO) over silicon dioxide, silicon nitride or copper during chemical mechanical polishing. Colloids Surf. A 371 (1—3), 131-136. 

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