The present invention relates to compounds of the formula I in which substituents R2 and R3 are arranged in trans-configuration: wherein: R1 is H or C1-C6 alkyl; C3-C7 cycloalkyl; R2 is phenyl, optionally substituted with 1 to 5 substituents independently selected from the group comprising OH, C1-C6-alkyl, halogen, nitro, cyano, SH, SR4, trihalo-C1-C6-alkyl, C1-C6-alkoxy and phenyl, wherein R4 is C1-C6 alkyl; R3 is phenyl substituted with OR5 wherein R5 has the formula (II), (III) or (IV) wherein Y is chosen from NHR4, NR42, NHCOR4, NHSO2R4, CONHR4, CONR4, CONR42, COOH, COOR4, SO2R4, SOR4, SONHR4, SONR42, a C3-C7 heterocyclic ring, saturated or unsaturated, containing one or two heteroatoms independently selected from the group consisting of O, S and N, optionally being substituted with 1 to 3 substituents independently selected from the group comprising H, OH, halogen, nitro, cyano, SH, SR4, trihalo-C1-C6-alkyl, C1-C6-alkyl and C1-C6-alkoxy, preferably NHR4, NR24, or a nitrogen heterocycle, wherein R4 is as defined above, and the esters, ethers, and salts of the compounds of formula I, optionally along pharmaceutically acceptable excipients, a process for the preparation of the same, and a method of preventing and/or treating estrogen-related disease conditions in a subject using compounds of formula 1, or its salts, optionally along with pharmaceutically acceptable excipients.