Novel opiates and antagonists. 6. 7-Alkyl-6,7-didehydromorphinans

A method for preparing a variety of 7-alkyl-6,7- didehydromorphinans from the corresponding 6- morphinanones is described. The key intermediates in this sequence are the 7-formyl derivatives. The two epimeric B/C-trans-7-(1- hydroxypentyl ) morphinans ( 16a ,b) are stereochemically similar to the endo- ethanotetrahydrooripavines and are extremely potent in the mouse writhing test. The corresponding B/C-cis -7-(1- hydroxypentyl ) morphinans are inactive in this test.