Tetrolaldehydes or crotonaldehydes containing an adequate functional substituent in the y- position seem to be suitable as the dienophiles for the preparation of the Diels-AIder adducts which can be used as the key intermediates for a certain synthetical project concerning f-ionone analogues. In spite of their apparently simple structure, such compounds and their Diels-AIder adducts have hitherto scarcely been reported. One of ...