SYNTHESIS OF MONOPROTECTED DERIVATIVES OF HOMO-BIFUNCTIONAL MOLECULES

Selective derivatization of one of the two functional groups in a symm etrical homo-bifunctional molecule is always an uphill synthetic task. A novel method for synthesis of mono-protected homo-bifunctional poly (ethylene glycol) (PEG) is described in this work. The methodology uti lizes a combination of two protecting groups that are orthogonal to ea ch other for the introduction of one of these groups into symmetrical homo-bifunctional PEG polymers. Different well-known protecting groups , namely the carbobenzyloxy (Z) and the t-butyloxycarbonyl (Boc) group s, have been evaluated for this particular purpose. The approach appea rs to be straightforward in terms of separation of desired products fr om other non-desirable products or reactants. The methodology describe d here might be applicable to any symmetrical homo-bifunctional molecu lar substance and for synthesis of its corresponding monoprotected der ivatives.