[摘要]：The treatment of morphinans I (R = Me, Et, i-Bu, cyclopropylmethyl, allyl) with NaH and MsCl provided very stable iminium salts II possessing propellane skeleton. One of the synthesized iminium salts, II (R = i-Bu), was crystd. and its structure was detd. by X-ray crystallog. The natural bond orbital anal. suggested that the stability of the iminium should result from the stereoelectronic effect (hyperconjugation) attributed to their own structures.
