An efficient synthesis of orthogonally protected spermidine

A major problem in the use of spermidine for the synthesis of biologically interesting compounds is the selective orthogonal protection of the three different amino groups. Our approach is based on the Fukuyama reaction, starting from putrescine and 3-amino-1-propanol and affording N-8-benzyloxycarbonyl-N-1-tert-butyloxycarbonyl-N-4-(2-nitro-benzenesulfonyl)spermidine (5) in 5 steps in high yield.