The acetolysis of some ω-Cyclooctatetraenylalkyl p-Nitrobenzenesulphonates

Abstract

The synthesis and solvolytic behaviour (in buffered acetic acid) of the p-nitrobenzenesulphonate esters of 2-cyclooctatetraenylethanol, 3- cyclooctatetraenylpropan-1-ol and 4-cyclooctatetraenyl-butan-1-ol are described. For comparison with the cyclooctatetraenylalkyl derivatives, kinetic data for the corresponding ω-(cyclooct-1?-enyl)alkyl and ω- cyclooctyl p-nitrobenzenesulphonates are reported.     Kinetic and product studies have shown that π-bond participation occurs in the acetolysis of 2-cyclooctatetraenylethyl p- nitrobenzenesulphonate. The nature of the cyclized products, which amount to 95 % when 1.1 equiv. of sodium acetate (the buffer) are used, depends markedly on the concentration of buffer.     Acetolysis of 3-cyclooctatetraenylpropyl p-nitrobenzenesulphonates gives at least 98% non-cyclized products. A probable cyclized product (<2%) is tentatively identified as bicyclo[6,3,0]-undeca-1,3,5,7- tetraene.     Cyclized products (44%) are formed in the acetolysis of 4- cyclooctatetraenylbutyl p-nitrobenzene-sulphonate.