Zeolite beta induced rearrangement of allyl benzyl ethers. 6. Variation ofthe aromatic part and synthesis of dihydronaphthalene derivatives

The zeolite beta induced rearrangement of substituted allyl benzyl ethers t o give 4-arylbutanals was investigated with respect to the substituents in the aromatic ring. In some cases the resulting aldehydes cyclized spontaneo usly to give dihydronaphthalene derivatives. The rearrangement and also the ring closure to dihydronaphthalenes failed or gave poor yields in cases wh ere too weak electron-donating substituents were present in the aromatic ri ng. Also the dimensions of the pore size of the zeolite in relation to the transition state of the cyclization seemed to be of importance. Replacement of the benzylic part with other structures potentially capable of stabiliz ing cationic centers have hitherto not resulted in successful rearrangement s.