A modified opioid is provided comprising modified morphine molecules, wherein for each morphine molecule, one or more carbon atoms are replaced with silicon atoms. A method is further provided for modifying an opioid comprising morphine molecules, said method comprising the step of replacing one or more carbon atoms with silicon atoms.
[Structure: see text] The morphinan skeleton was effectively synthesized by an intramolecular Mannich-type reaction. Further transformation led to totalsynthesis of morphine.