THE SYNTHESIS OF PRECISELY STRUCTURED POLYURETHANES .1. MONOMER SYNTHESIS

The synthesis of a series of bifunctional siloxymethyl isocyanate mono mers, required for the solid phase synthesis of structurally defined p olyurethane oligomers and copolymers is described. Thus, the MDI mimic s 2, 3 were synthesised via a desymmetrisation sequence from di-p-toly lmethanone and the tert-butyld iphenylsiloxymethylaryl isocyanates 19, 22 and tert-butyldiphenylsiloxyethoxyethyl isocyanate 25, an aliphati c variant, which were all synthesised from commercially available amin o alcohols.