Novel prodrug approach to amprenavir-based HIV-1 protease inhibitors via O-->N acyloxy migration of P1 moiety

We have developed a new approach to prodrugs, which utilizes a pH-induced intramolecular O-->N migration of an acyloxy group in carbonate moiety to a free amino moiety at neutral pH. This method is exemplified by facile rearrangement of highly water-soluble prodrug 3 to carbamate 4, a close analogue of HIV-1 protease inhibitor Amprenavir. The O-->N acyloxy migration is unprecedented in the context of prodrugs and it enables a high atom economy due to recycling of the 'pro' moiety.