The conservation of the cultural heritage requires the development of new materials having specific characteristics that encompass particular attention to durability and efficacy. We approached this problem by synthesizing polyacrylic esters containing variable amounts of fluorine in the α-position of the main chain. These products were obtained from the copolymerisation of ammonium 2-fluoroacrylate and acrylic acid. The polyacrylic acids were esterified using different procedures. The polyester characteristics vary in relation to the polymerisation procedures and degree of esterification. The best esterification results, were obtained using a reaction catalyzed by BF3 or TMSCl. These materials show good properties and are of potential interest for their use as protective agents for stone conservation.

Abstract1,3‐Dipolar cycloaddition of the title compound (I) with equimolar amounts of diazomethane (II) produces the oxazabicyclo(3.1.0)hexene derivative (IV), obtained via the intermediate adduct (III) by elimination of nitrogen, and the isoxazole derivative (V); 40% of the starting material (I) are recovered.

AbstractDiazomethane (IIa) and 2‐diazopropane (IIb) undergo cycloaddition reaction with the isoxazole derivative (I) to yield the unstable adducts (III) which release nitrogen to give the bicyclic derivatives (IV).

AbstractThe nitroisoxazole (IV), prepared from nitroacetophenone oxime (I) and benzoylformyl chloride (II), reacts with one equivalent of diazomethane (V) to produce a mixture of the pyrazoloisoxazole (VI) and the cyclopropane derivative (VII).

The nitroester (1) was shown to give rise to 1,3-dipolar cycloadditions with diazomethane and 2-diazopropane,affording the bicyclic derivatives (4) and (5)via the unstable primary cycloadducts (2) and (3), respectively.