Tetrahedron Letters,Vol.28,No.41,pp 4893-4896,1987 0040-4039/87 $3.00 + .OO Printed in Great Britain Pergamon Journals Ltd. CARROL REARRANGEMENT ON THE SURFACE OF CHROMATOGRAPHIC GRADE ALUMINA S.I.Pogrebnoi, Y.B.Kalyan, M.Z.Krimer Institute of Chemistry, Grosul street, zyxwvutsrqponmlkjihgfedcbaZYXWVUT 3, Kishinev, USSR W.A.Smit*, Zelinsky Institute of Organic Chemistry, Leninsky pr. 47, Moscow, USSR Abstract. Thermolysis on the surface of A1203 is proposed as a mild and con- venient preparative method for /3,3/-sigmatropic Carrol rearrangement of acetoacetic esters of tertiary ally1 alcohols into respective )3&unsatu- rated ketones. As was reported earlier', the rate of intramolecular cyclization of di- cobalthexacarbonyl complexes of allylpropargyl ethers into the derivatives of 3-oxabicyclo p,3,0] octane (/2+2+1/ - cycloaddition, Khand-Pauson reac- tion) is greatly enhanced provided the reaction is carried out in the ab- sence of any solvents with the substrates applied to the surface of SiO2 or A120. This effect has been ascribed to the preferential stabilization of the coiled conformation of the adsorbed acyclic substrate due to the res- trictions of its conformational mobility imposed by the interaction with the surface adsorption centers. It has been also suggested' that quite simi- lar effects of the adsorption promotion should be operative in case of other antropy controlled intramolecular reactions. The present study has been undertaken to check the validity of this suggestion for the model example of Carrol reaction 2a*b, a variant of /3,3/- sigmatropic Claisen rearrangement 2csd (Scheme I). Scheme 1 I h According to the conventional procedure Carrol reaction is carried by a prolonged heating of the acetoacetic ester of ally1 alcohols (as a 4893