132921-97-2Relevant articles and documents
Enantioselective iridium-catalyzed vinylogous reformatsky-aldol reaction from the alcohol oxidation level: Linear regioselectivity by way of carbon-bound enolates
Hassan, Abbas,Zbieg, Jason R.,Krische, Michael J.
supporting information; experimental part, p. 3493 - 3496 (2011/06/09)
Reformatsky reinvented: Highly enantioselective vinylogous Reformatsky-type addition has been achieved from the alcohol oxidation level with linear regioselectivity through carbon-bound enolates (see scheme; Boc=tert- butoxycarbonyl). Complete levels of c
Synthesis of trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine opioid antagonists: Application of the cis-thermal elimination of carbonates to alkaloid synthesis
Werner, John A.,Cerbone, Louis R.,Frank, Scott A.,Ward, Jeffrey A.,Labib, Parviz,Tharp-Taylor, Roger W.,Ryan
, p. 587 - 597 (2007/10/03)
Improved syntheses of two trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine opioid antagonists from 1,3-dimethyl-4-piperidinone are described. The 1,3-dimethyl-4-arylpiperidinol 23 was selectively dehydrated in a two step process to the 1,3-dimethyl-4-aryl-1,2,3,6-tetrahydropyridine 26 by the cis-thermal elimination of the corresponding alkyl carbonate derivative at 190°C. In the presence of a basic nitrogen, the success of the elimination was found to be critically dependent upon the nature of the carbonate alkyl group, with Et, i-Bu, and i-Pr being preferred (90% yield). Alkylation of the metalloenamine, formed by deprotonation of 26 with n-BuLi, proceeded regio- and stereospecifically to give the trans-3,4-dimethyl-4-aryl-1,2,3,4-tetrahydropyridine 27, which was converted in three steps to the common intermediate, (3R,4R)-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine. LY255582, a centrally-active opioid antagonist, and LY246736-dihydrate, a peripherally-active opioid antagonist, were prepared from 1,3-dimethyl-4-piperidinone in 11.8% yield (8 steps) and 6.2% yield (12 steps), respectively.
Regioselective reductive opening of 2,3-epoxy alcohol derivatives with lithium borohydride in a solid state
Sugita, Keisuke,Onaka, Makoto,Izumi, Yusuke
, p. 7467 - 7468 (2007/10/02)
2,3-Epoxy alcohol derivatives were reduced regiospecifically with lithium borohydride in a solid state suspended in hexane to yield the corresponding C-3 opening products.