A method for generating human milk oligosaccharides (HMOs) or precursors thereof, compounds obtainable by the method, and uses and compositions involving such compounds. The method comprising the steps of a) providing at least one donor selected from the group of compounds of any of formulae 5 to 10, b) providing at least one acceptor from a group of lactose, LNT, LNnT and derivatives thereof, c) providing at least one enzyme comprising a transglycosidase activity and/or a glycosynthase activity, d) preparing a mixture of the at least one donor, at least one acceptor and at least one enzyme provided in steps a), b) and c); and e) incubating the mixture prepared according to step d).