Synthesis of Terminal Thiazoles from <i>N</i>-Protected Amino Acids and a Study of Their Antibacterial Activities
作者:H. S. Lalithamba、K. Uma、T. S. Gowthami、G. Nagendra
DOI:10.1080/00304948.2020.1721959
日期:2020.5.3
located thiazole derivatives. Several methods for the synthesis of thiazoles have been reported as follows: (i) thiazolecontaining amino acids were synthesized by condensation-cyclization, (ii) Ling and his group prepared 1,2,4-triazole-linked thiazole derivatives from the reaction of a-bromo substituted acetophenones and thiourea, (iii) Wardakhan and his co-workers synthesized several thiazole derivatives
Efficient stereoselective synthesis of dolastatin 10, an antineoplastic peptide from a sea hare
作者:Yasumasa Hamada、Kyoko Hayashi、Takayuki Shioiri
DOI:10.1016/s0040-4039(00)92123-3
日期:1991.2
The stereoselective and efficient synthetic route to dolastatin 10, an antineoplastic peptide from a sea hare, has been developed. Dolaproine, one of the unusual constituents, was prepared in a highly stereoselective manner by the Evans aldol methodology.
bromoacetal, but the amino acid thus obtained showed no perceptible optical activity. The racemic amino acid, however, could be resolved into its antipodes by treating its phthalyl derivative with brucine. Thus, the (+)-amino acid, a constituent of bottromycin, was isolated in a pure state; it was determined to belong to the L-series by examining its optical behavior. This amino acid was proved to racemize
为了获得具有旋光活性的β-(2-噻唑基)-β-丙氨酸,将N-酰基-L-天冬氨酸α-硫代酰胺-β-甲酯与溴乙缩醛缩合,但由此获得的氨基酸未见明显光学活性。然而,外消旋氨基酸可以通过用马铃薯碱处理其邻苯二甲酰衍生物而分解为其对映体。因此,(+)-氨基酸,肉毒杆菌素的一种成分,以纯净的状态被分离出来;通过检查其光学行为,确定它属于 L 系列。证明该氨基酸在肉毒杆菌素酸水解条件下容易外消旋化。
A new efficient synthesis of (S)-dolaphenine ((S)-2-phenyl-1-(2-thiazolyl)ethylamine), the C-terminal unit of dolastatin 10
作者:Naoko Irako、Yasumasa Hamada、Takayuki Shioiri
DOI:10.1016/s0040-4020(01)88264-8
日期:1992.1
Four methods for the preparation of (S)-dolaphenine ((S)-2-phenyl-1-(2-thiazolyl)ethylamine, 2), which constitutes the C-terminal unit of dolastatin 10 (1) having strong anticancer activity, has been investigated. Of these, the most efficient one involved the acylation of 2-lithiothiazole with N-methoxy-N-methylphenylacetamide (8), asymmetric reduction with (+)-diisopinocampheylchloroborane (11g), followed by the modified Mitsunobu reaction utilizing diphenyl phosphorazidate.