9-Bromo-11-oxo-hexahydrocannabinol (5) was prepared from the ketocannabinoid 3b via the epoxysulfone 4. The dehydrobromination of the bromoaldehyde 5 could be controlled to give either the thermodynamically more stable Δ8-aldehyde 2c, or the Δ9-aldehyde 1c by an intramolecularly assisted elimination. Reduction of the unsaturated aldehydes gave the allylic alcohol metabolites 2a and 1a, respectively.
9-溴-11-酮-大麻酚(5)是通过经过环氧磺酮4处理的酮大麻酚3b制备的。 溴醛5的脱溴反应可以控制,从而得到热力学上更稳定的Δ8-醛2c,或者通过分子内辅助消除得到Δ9-醛1c。 对不饱和醛的还原分别产生了烯丙醇代谢物2a和1a。