Enantioselective Synthesis of Diamino Dicarboxylic Acids.

The preparation of alkyl diamino dicarboxylic acids with high optical purity (100% ee, >98.5% de) and high yields based on asymmetric catalytic hydrogenation is described. The required prochiral precursors are prepared from dialdehydes and Z-, Boc-, and acetyl-protected phosphonoglycines.

Large-scale synthesis of hematoregulatory nonapeptide SK&F 107647 by fragment coupling.

Linear and convergent routes for the large-scale preparation of the hematoregulatory nonapeptide (Glp-Glu-Asp)2-DAS-(Lys)2 (2, SK&F 107647) were investigated. A convergent approach ('3 + 2'-route employing Boc-and benzyl ester protecting groups) was selected for the preparation of multihundred-gram quantities of 2. Key steps were the preparation and the coupling of tripeptide hydrochloride (HCl.

[Thiophene as a structural element of physiologically active substances. 20. Thiophene analogs of the leukotriene D4 antagonist Ro 23-3544].

The synthesis of 6-Acetyl-7-[[5-(5-acetyl-4-hydroxy-3-propyl-2-thienyl- oxy)pentyl]oxy]-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid (1), a thiophene analogue of the leukotriene antagonist Ro 23-3544, is described. Compound 1 shows almost no effect on leukotriene D4 induced broncho-constriction on anesthesized guinea pigs.

[Thiophene as a structural element of physiologically active compounds. 19. The synthesis of substituted (6H-thieno[2,3-b]pyrrol-4-yl)phenylmethanones].

The synthesis of 4-Methoxyphenyl-[5-methyl-6-(2-(4-morpholinyl)-ethyl)-6H-thieno[2,3- b]pyrrol-4-yl)phenylmethanone (1), a thiophene analogue of the analgesic Pravadoline B, is described. Starting with the acetylprotected thienylhydrazine 2b compound 7 was obtained in a Fischer-analogue cyclication in two steps. Use of the BOC-protected thienylhydrazine 2a yielded the pyrazol 5.