Preparation of 9a-Fluorinated Sesquiterpenic Drimanes and Evaluation of Their Antifeedant Activities

19 pages, figures, and tables statistics.The preparation of 9α-fluoro analogues of both natural and unnatural drimane-type sesquiterpenes is described. Their synthesis began with the initial preparation of methyl 8-keto- 12-nordriman-11-oate from β-ionone and entailed the electrophilic fluorination of C-9 for the stereoselective introduction of the fluorine atom. The drimane skeleton was completed from the intermediate 9α-fluoro-8-keto-12-nordrimane system by means of different reactions at the C-8 ketone carbonyl group, essentially Wittig methylenation, cyanohydrin formation or palladium-catalysed carbonylation of the corresponding enol triflate. Further manipulation of the functionalization derived from these key reactions allowed the preparation, among others, of 9α-fluorodrimanes, which are structurally and functionally related to albicanic acid, drimenin and olepupuane. Also described are the reactivities of some of the fluorine-containing systems prepared and a comparative study of the antifeedant activities of a selection of 9α-fluorodrimanes and the corresponding hydrogen analogues against several insect species with different feeding ecologies (Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi), which revealed a significant increase in the antifeedant activities of some of the fluorinated drimane analoguesPeer reviewe

Is It Prime Time for Alpha2-Adrenocepter Agonists in the Treatment of Withdrawal Syndromes?

The need to treat withdrawal syndromes is a common occurrence in outpatient, inpatient ward, and intensive care unit (ICU) settings. A PubMed and Google Scholar search using alpha2-adrenoreceptor agonist (A2AA), specific A2AA agents, withdrawal syndrome and nicotine, and alcohol and opioid withdrawal terms was performed. A2AA agents appear to be able to modulate many of the signs and symptoms of significant withdrawal syndromes but are also capable of significant side effects, which can limit clinical use. Non-opioid oral A2AA agent use for opioid withdrawal has been well established. Pharmacologic combination therapy that utilizes A2AA agents for withdrawal syndromes appears promising but requires further formal testing to better define which other agents, under what condition(s), and at what A2AA doses are needed. The A2AA dexmedetomidine may be useful as an adjunctive agent in treating severe alcohol withdrawal syndromes in the ICU. In general, the current data does not support the routine use of A2AA as the primary or sole agent to treat ethanol/alcohol or nicotine withdrawal syndromes. Specific A2AA agents such as lofexidine has been shown to have a primary role in non-opioid-based treatment of opioid withdrawal syndrome and dexmedetomidine in combination with benzodiazepines has been shown to have potential in the treatment of severe ICU-based alcohol withdrawal syndrome