| abstract |
There are described novel trans-2-acylaminocyclohexyloxyacyldipeptides of formula I <CHEM> wherein R1 represents -CO-R6, -SO2-R7 or <CHEM> R6 is C1-C18 alkyl or C1-C18 alkoxy, R7 is C1-C18 alkyl or an optionally substituted phenyl group, Y is =O, =S or =NH; R2 = R3 and represent -H or C1-C12 alkyl, R4 represents -OR8 or -NHR9, R8 is -H, C1-C8 alkyl or benzyl, R9 is -H, a straight or branched chain C1-C18 alkyl group or benzyl group; R5 represents -OR9 or -NHR9, and novel (1R,2R)- and (1S,2S)-trans-2-acylaminocyclohexyloxyacetyldipeptides of the formulas Ia and Ib <CHEM> wherein R1 is -CO-R6, R6 is C1-C18 alkyl, R2 is -H, R3 is -H or C1-C12 alkyl, R4 is -OR8 or -NHR9, R8 is -H, C1-C8 alkyl or benzyl, R9 is -H, C1-C18 alkyl or benzyl, R5 is -OR9 or -NHR9 Compounds of formula I are obtained by reacting carboxylic acids of formula II <CHEM> with dipeptides of formula III <CHEM> wherein the substituents have the above meanings. Compounds of formulas Ia and Ib are obtained by reacting (1'R,2'R)- or (1'S,2'S)-trans-2-(2'-acylaminocyclohexyloxy) acetic acids of formulas IIa and IIb <CHEM> with dipeptides of formula III <CHEM> wherein the substituents have the above meanings. Compounds of formulas Ia or Ib can also be obtained by separating mixtures of diastereoisomers of formula I by column chromatography on silica gel. Compounds of formula I, Ia and Ib and the pharmaceutically acceptable alkali salts thereof show immunomodulatory and antitumour activities and can be used in the preparation of medicaments. |