The A2B2-core 1a was synthesized by a double Michael-addition between mono Z-protected Ethane-1,2-diamine (5a) and t-butyl acrylate. The Z-group was removed by catalytic hydrogenation and a new double Michael-addition with benzyl acrylate gave compound 1a. The ABAB-core 1b was synthesized from N,N'-dibenzyl-Ethane-1,2-diamine (6b) and t-butyl acrylate to the N,N'-diben-zylamine 7b in quantitative yield. Catalytic hydrogenation using Pearlman's catalyst removed the benzyl-groups in quantitative yield giving compound 8b, which gave the ABAB-core 4a in 90% yield after a double Michael-addition with benzyl acrylate . The AB3-core 1c was synthesized in a similar manner starting from N-benzyl-Ethane-1,2-diamine (6a) . We found that the Michael-additions between primary amines and acrylates proceed in a stepwise manner with very good selectivity for mono-addition. Furthermore, the mono-and the bis-adducts are very simple to separate by column chromatography. This was utilized in the synthesis of the ABCD-core 1d as shown in Scheme 2, where mono Z-protected Ethane-1,2-diamine (5a) undergoes a mono Michael-addition with t-butyl acrylate to form compound 3g, which undergoes a second Michael-addition with methyl acrylate to give dendron 3e. Deprotection by catalytic hydrogenation gives the amine 9d and a new sequence of mono Michael-additions gives the ABCDcore 1d. The protected dendrons are synthesized as shown in Scheme 1 (3a), Scheme 2 (3e) and Scheme 3 (3b, 3c, 3d and 3f) starting either from carbamate protected (BOC or Z) or benzylated diamines. The synthesis of dendrimers from the building blocks is exemplified in Scheme 4, which shows the synthesis of the unsymmetrical dendrimer 2g by deprotection of the benzylester in core 1a by catalytic hydrogenation and PYBOP-coupling of the dicarboxylic acid with dendron 4b. Due to the flexibility of the synthetic scheme with respect to cores and dendrons, there is a need for a short hand notation for the structure of the dendrimers; the number of carbons between the amino-group and the esters in the dendrons is always three carbons in the present, but the ester groups vary as well as the number of carbons between the two amino groups in the dendron. In the case of dendrimer 2g starting on the left side: There are two benzyl esters bound to a C2-dendron and one t-butyl ester bound to a C2-core with the Scheme 3: Synthesis of dendron 3f Scheme 4: The principles of the synthetic scheme for dendrimer synthesis illustrated by the synthesis of compound 2g (Bn2C3Bn2C3-C3core-C3Bu t 2C3Bu t 2)