y-Lactams are important intermediates in synthetic routes to five-membered heterocyclic compounds. Moreover, tetramic acids and 3-pyrrolin-2-ones represent a diverse and profoundly important family of biologically active secondary metabolites, many of which have potential use in both medicine and agriculture.1 Synthetic interest in this class of molecules has been intense, particularly in the past decade.2
Remote ketone-functionalized aryl-and alkylcopper reagents have been synthesized by the use of a highly activated form of zero-valent copper. 5-Bromc-2-pentanone and 4-iodobenzophenone undergo oxidative addition with activated copper to form 5-cuprio-bpentanone and 4-cupriobenzophenone, respectively. These, in turn, can be cross-coupled with alkyl halides to produce the corresponding alkylated ketones and with acid chlorides to form the corresponding diketones. By use of this methodology, a two-step, one-pot synthesis of methyl (E)-9-oxo-2-decenoate and 8-nonen-Bone have been achieved. The former compound is the methyl ester of the 'queen substance" of the honey bee, and the latter is part of an "attractant mixture" for cheese mites found in cheddar cheese. These syntheses were accomplished by converting commercially available 6-bromo-2-hexanone to 6-cuprio-2-hexanone followed by cross-coupling with commercially available methyl 4-bromocrotonate and allyl bromide, respectively.(1) Cope, A. C.; Hardy, E. M. J. Am. Chem. Soc. 1940,62,441. Cope, A. C.; Hofmann, C. M.; Hardy, E. M. Ibid. 1941,63,1862. Cope, A. C.; Levy, H. Ibid. 1944,66, 1684.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.