Carbocations, Fast Rearrangement Reactions, and the Isotopic Perturbation Method

New avenues for the synthesis of ent-kaurene diterpenoids

“…18 Ent-trachylobane (3) would be the deprotonated form of this carbocation, and the subsequent isolation of the first ent-trachylobane diterpene in 1965 gave support to this hypothesis. However, with Olah's studies of carbenium ion rearrangements 19 …”

“…Peroxiredoxins (Prx) incorporate a conserved cysteine -also referred to as the peroxidatic cysteine (Cp) -that serves as the site of oxidation by peroxides. In 2012, Chen and coworkers 44 reported adenanthin (19) to induce differentiation of acute promyelocytic leukemia cells (APL). Adenanthin (19) is the first natural product shown to target specific cysteines of Prx1 and PrxII and in turn inhibit their peroxidase activities.…”

“…In 2012, Chen and coworkers 44 reported adenanthin (19) to induce differentiation of acute promyelocytic leukemia cells (APL). Adenanthin (19) is the first natural product shown to target specific cysteines of Prx1 and PrxII and in turn inhibit their peroxidase activities. Adenanthin (19) is proposed to act as a Michael-acceptor and in turn covalently modifies Cys173 in PrxI and Cys172 in PrxII.…”

“…Adenanthin (19) is the first natural product shown to target specific cysteines of Prx1 and PrxII and in turn inhibit their peroxidase activities. Adenanthin (19) is proposed to act as a Michael-acceptor and in turn covalently modifies Cys173 in PrxI and Cys172 in PrxII. The experimental data strongly suggests that PrxI and PrxII are direct targets of adenanthin's induction of APL cell differentiation.…”

“…E.J. Corey's strategy to access nominal neotripterifordin which led to the structural revision of neotripterifordin 19. …”