A process for the preparation of a compound of formula: wherein: the dotted line denotes a bond which is single or double, - R1 and R '1 are the same or different and represent H or CH 3, - R2 is H, CH 3 or C 2 H 5, - R 3 is -NRR' wherein R and R' are the same or different and are selected from the group consisting of: - H, - (CH 2)n-OH wherein n is an integer comprised between 1 and 4, - (CH 2)n-NHP wherein n is an integer comprised between 1 and 6 and P is H or a protecting group; - (CH 2)n-NP-(CH 2)m-NHP' wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, and P and P' are the same or different and represent H or a protecting group; - (CH 2)n-NP-(CH 2)m-NP'-(CH 2)p-NHP" wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, p is an integer comprised between 1 and 6, and P, P' and P" are the same or different and represent H or a protecting group; - (CH 2)n-X wherein n is an integer comprised between 1 and 4 and X = imidazol, indol or phenyl, optionally substituted with one or several groups chosen among OH, NH 2 or SH. - R4 is OH, acetoxy or butoxy, said process comprising: ( a) reacting an α-epoxy compound of formula: wherein R1, R'1, R2 and R4 have the same meaning than in formula and the dotted line denotes a bond which is single or double, with a monoamine or polyamine of formula: R3H wherein R3 has the same meaning than in formula in a reaction medium at reflux; (b) recovering compound from the reaction medium; wherein an alcohol comprising 3 to 5 carbon atoms or a mixture thereof is used as a solvent in the reaction medium. the dotted line denotes a bond which is single or double, - R1 and R '1 are the same or different and represent H or CH 3, - R2 is H, CH 3 or C 2 H 5, - R 3 is -NRR' wherein R and R' are the same or different and are selected from the group consisting of: - H, - (CH 2)n-OH wherein n is an integer comprised between 1 and 4, - (CH 2)n-NHP wherein n is an integer comprised between 1 and 6 and P is H or a protecting group; - (CH 2)n-NP-(CH 2)m-NHP' wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, and P and P' are the same or different and represent H or a protecting group; - (CH 2)n-NP-(CH 2)m-NP'-(CH 2)p-NHP" wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, p is an integer comprised between 1 and 6, and P, P' and P" are the same or different and represent H or a protecting group; - (CH 2)n-X wherein n is an integer comprised between 1 and 4 and X = imidazol, indol or phenyl, optionally substituted with one or several groups chosen among OH, NH 2 or SH. - R1 and R '1 are the same or different and represent H or CH 3, - R2 is H, CH 3 or C 2 H 5, - R 3 is -NRR' wherein R and R' are the same or different and are selected from the group consisting of: - H, - (CH 2)n-OH wherein n is an integer comprised between 1 and 4, - (CH 2)n-NHP wherein n is an integer comprised between 1 and 6 and P is H or a protecting group; - (CH 2)n-NP-(CH 2)m-NHP' wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, and P and P' are the same or different and represent H or a protecting group; - (CH 2)n-NP-(CH 2)m-NP'-(CH 2)p-NHP" wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, p is an integer comprised between 1 and 6, and P, P' and P" are the same or different and represent H or a protecting group; - (CH 2)n-X wherein n is an integer comprised between 1 and 4 and X = imidazol, indol or phenyl, optionally substituted with one or several groups chosen among OH, NH 2 or SH. - H, - (CH 2)n-OH wherein n is an integer comprised between 1 and 4, - (CH 2)n-NHP wherein n is an integer comprised between 1 and 6 and P is H or a protecting group; n is an integer comprised between 1 and 6 and P is H or a protecting group; - (CH 2)n-NP-(CH 2)m-NHP' wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, and P and P' are the same or different and represent H or a protecting group; n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, and P and P' are the same or different and represent H or a protecting group; - (CH 2)n-NP-(CH 2)m-NP'-(CH 2)p-NHP" wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, p is an integer comprised between 1 and 6, and P, P' and P" are the same or different and represent H or a protecting group; wherein n is an integer comprised between 1 and 6, m is an integer comprised between 1 and 6, p is an integer comprised between 1 and 6, and P, P' and P" are the same or different and represent H or a protecting group; - (CH 2)n-X wherein n is an integer comprised between 1 and 4 and X = imidazol, indol or phenyl, optionally substituted with one or several groups chosen among OH, NH 2 or SH. - R4 is OH, acetoxy or butoxy, ( a) reacting an α-epoxy compound of formula: wherein R1, R'1, R2 and R4 have the same meaning than in formula and the dotted line denotes a bond which is single or double, with a monoamine or polyamine of formula: R3H wherein R3 has the same meaning than in formula in a reaction medium at reflux; (b) recovering compound from the reaction medium;