Probes for narcotic receptor mediated phenomena. 37. Synthesis and opioid binding affinity of the final pair of oxide-bridged phenylmorphans, the ortho- and para-b-isomers and their N-phenethyl analogues, and the synthesis of the N-phenethyl analogues of the ortho- and para-d-isomers.

In the isomeric series of 12 racemic topologically rigid N-methyl analogues of oxide-bridged phenylmorphans, all but two of the racemates, the ortho- and para-b-oxide-bridged phenylmorphans 20 and 12, have remained to be synthesized. The b-isomers were very difficult to synthesize because of the highly strained 5,6-trans-fused ring junction that had to be formed. Our successful strategy required functionalization of the position para (or ortho) to a fluorine atom on the aromatic ring using an electron-withdrawing nitro group to activate that fluorine.

Probes for narcotic receptor-mediated phenomena. 33. Construction of a strained trans-5,6-ring system by displacement of a nitro-activated aromatic fluorine. synthesis of the penultimate oxide-bridged phenylmorphans.

The synthesis of the ortho- and para-e isomers in the oxide-bridged 5-phenylmorphan series of rigid tetracyclic compounds was accomplished via rac-5-(2-fluoro-5-nitrophenyl)-2-methyl-2-azabicyclo[3.3.1]nonan-9beta-ol ((+/-)-10), an intermediate containing an aromatic nitro-activated fluorine atom.

Synthesis of rac-(1R,4aR,9aR)-2-methyl-1,3,4,9a-tetrahydro-2H-1,4a-propanobenzofuro[2,3-c]pyridin-6-ol. An unusual double rearrangement leading to the ortho- and para-f oxide-bridged phenylmorphan isomers.

In an attempt to obtain the para-f isomer, rac-(1R,4aR,9aR)-2-methyl-1,3,4,9a-tetrahydro-2H-1,4a-propanobenzofuro[2,3-c]pyridin-6-ol, via mesylation of an intermediate 9[small alpha]-hydroxyphenylmorphan, we obtained, instead, a rearranged chloro compound with a 5-membered nitrogen ring, 7-chloro-3a-(2,5-dimethoxyphenyl)-1-methyl-octahydroindole. This indole underwent a second rearrangement to give us the desired para-f isomer. The structures of the intermediate indole and the final product were unequivocally established by X-ray crystallography.