| abstract |
The invention relates to compounds of general formula (A), where R is COOH, COOR<1>, CH2-OH, C(=O)NR<2>R<3>, CN, CH2NR<2>R<3>, C(=O)-Z, CH2-Z, or a substituent in accordance with formula (C), R<4> is COOH, COOR<1>, CH2-OH, C(=O)NR<2>R<3>CN, CH2NR<2>R<3> or a substituent in accordance with formula (D), where R<1> is CxH2x+1 with x = 1,2,3,4,5, -CH2-C6H5 or -C6H5, R<2>, R<3> independently of each other are H, CxH2x+1 with x = 1,2,3,4,5, -CH2-C6H5 or -C6H5, Y independently of each other are benzoyl, formyl, acetyl, trifluoroacetyl, glycosyl or silyl; Z is an organic group linked via an O, N or S, and n is 1,2,3,4 or 5, and the absolute configuration at C* can be both S and R, as well as the salts of the compounds, especially alkali, alkaline-earth or ammonium salts, where R is not CH2NH2 or CN if n = 3 or 4 and R<4> = formula (D) with Y = H, and R is not formula (C) with Y = H if n = 2,3,4,5 and R<4> = formula (D) with Y = H, and R is not CH2-OH or COOH if R<4> = formula (D) with Y = H and n = 4 and the absolute configuration at the level of C* is S. |