Cyclic peptides. VI. Asymmetric hydrogenation of dehydroalanine or dehydroaminobutanoic acid residue in cyclodipeptides.
Cyclic peptides. VI. Asymmetric hydrogenation of dehydroalanine or dehydroaminobutanoic acid residue in cyclodipeptides.
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环肽。
DOI：
10.1111/j.1399-3011.1979.tb01870.x
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
N. Izumiya
中科院分区：
文献类型：
--
作者：
S. Lee;T. Kanmera;H. Aoyagi;N. Izumiya
采用Nitecki法和Fischer法合成了环（-L-氨酰基-L-Ser-），经对甲苯磺酰化和脱对甲苯磺酰化得到了几种环（-L-氨酰基-deltaAla-）（氨酰基= Ala，瓦尔，Leu，Phe，Pro和Lys（ε-Ac））。在室温和1个大气压下，在甲醇中使用钯黑进行环二肽中脱氢丙氨酸残基的双键的氢化。不对称氢化的程度通过用改进的Manning和摩尔程序测定L-和D-丙氨酸的量来评估。当L-缬氨酸作为手性源时，L-丙氨酸残基的手性诱导为98.4%，衍生自环（-L-Val-deltaAla-）。除L-脯氨酸外的L-氨基酸也能有效诱导显著的不对称氢化。环二肽中的α，β-氨基-α-氨基丁酸残基的氢化产生L-α-氨基丁酸残基，其具有与脱氢丙氨酸残基相同程度的有效手性诱导。以环（-L-Lys（epsilon-Ac）-deltaAla-）为原料，通过不对称氢化反应制备光学纯的L-丙氨酸。讨论了手性诱导的机理。
: Several cyclo(-L-aminoacyl-deltaAla-) (aminoacyl = Ala, Val, Leu, Phe, Pro and Lys (epsilon-Ac)) were prepared by tosylation and successive detosylation of cyclo(-L-aminoacyl-L-Ser-), which were synthesized via the Nitecki and Fischer methods. Hydrogenation of the double bond of dehydroalanine residues in cyclodipeptides was carried out using Pd black in methanol at 1-atm pressure and room temperature. The degree of asymmetric hydrogenation was assessed by determining the amounts of L- and D-alanine by a modified Manning and Moore procedure. When L-valine was used as a chiral source, L-alanine residue with chiral induction of 98.4% was derived from cyclo(-L-Val-deltaAla-). L-Amino acids other than L-proline also were effective in inducing remarkable asymmetric hydrogenation. Hydrogenation of alpha,beta-dehydro-alpha-aminobutanoic acid residues in cyclodipeptides produced L-alpha-aminobutanoic acid residues with effective chiral induction to the same extent as observed with dehydroalanine residues. Optically pure l-alanine was prepared from cyclo(-L-Lys(epsilon-Ac)-deltaAla-) via asymmetric hydrogenation. A mechanism of chiral induction is discussed.