Stereochemistry of catabolism of the RNA base uracil
作者:David Gani、Douglas W. Young
DOI:10.1039/p19850001355
日期:——
A mammalian enzyme system has been used to study the stereochemistry of the catabolism of the pyrimidine uracil (1) to the amino acid β-alanine (4). Use of [5-2H]- and [6-2H]-uracils and of 2H2O in the incubations yielded stereospecifically deuteriated samples of β-alanine. Assays, involving total synthesis of samples of β-alanine unambiguously labelled with deuterium in each of the four C–H bonds
哺乳动物酶系统已用于研究嘧啶尿嘧啶(1)分解为氨基酸β-丙氨酸(4)的立体化学。在培养中使用[5- 2 H]-和[6- 2 H]-尿嘧啶和2 H 2 O产生β-丙氨酸的立体特异性氘化样品。测定法,涉及β丙氨酸在四个C-H键的氘明确地标记的样本的总合成已经显示的是,在分解代谢过程中的第一步,尿嘧啶是通过二氢脱氢酶降低与整体抗加入氢气,在SI在C-6面和SI面在C-5。
Asymmetric induction in acyclic radical reactions: enantioselective syntheses of (s)-2-deuterioglycine and (r)-2-deuterioglycine.
作者:David P.G. Hamon、Ralph A. Massy-Westropp、Pasquale Razzino
DOI:10.1016/s0040-4020(01)80156-3
日期:1993.1
The (-)-8-phenylmenthol esters of N-Boc-glycine and N-Boc-2,2-dideuterioglycine were brominated with N-bromosuccinimide and the bromo compounds were reduced with tri-n-butyldeuteriostannane and tri-n-butylstannane respectively, to give the chiral glycine derivatives in 90% optical yield. Hydrolysis yielded the amino acid without racemisation.
Asymmetric induction in radical reactions: enantioselective syntheses of (S)-2-deuterioglycine and (R)-2-deuterioglycine
作者:David P. G. Hamon、Pasquale Razzino、Ralph A. Massy-Westropp
DOI:10.1039/c39910000332
日期:——
The (–)-8-phenylmenthol ester of N-Boc-glycine is brominated with N-bromosuccinimide and the bromo-compound is reduced with tri-n-butyldeuteriostannane to give the chiral glycine derivative in high optical yield which upon hydrolysis yields the amino acid without racemisation.
trichloroacetonitrile. The Overman's thermal rearrangement of 5a and 5b underwent with high diastereoselectivity to afford (Z)-allylic trichloroacetamide 6a and 6b, which in turn were converted to L- and D-alanine, respectively, by oxidative cleavage of the double bond and acid hydrolysis. The effectiveness of the present approach was assessed by using the simplest allylicalcohol system, i.e. (Z)- and
A divergent and highly enantioselective synthetic methodology not only for bothenantiomers of α-amino acids but for bothchirally deuterated glycines from a single starting material was developed by making use of stereocontrol with antiparallel double repulsion on the diacetone-D-glucos-3-ulose template.