01696nas a2200205   4500008004100000022001400041245020400055210006900259260023400328300001400562490000700576520064000583653002301223653001901246653002201265653003101287100001901318700002101337856013201358       2012                        eng d  a0033-454500aStereoselective construction of 5,11-methanomorphanthridine and 5,10b-phenanthridine structural frameworks: total syntheses of (+/-)-pancracine, (+/-)-brunsvigine, (+/-)-maritidine, and (+/-)-crinine0 aStereoselective construction of 511methanomorphanthridine and 51  a104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USAbVirginia Taylor; Astra Zeneca; Chem Sci Scotland; Eisai; EPSRC; Glasgow City Council; GSK; IUPAC; Pfizer; Scottish Enterprise; Syngenta; Univ StrathclydecMAY  a1597-16190 v843 a<p>The core structure of the complex pentacyclic 5,11-methanomorphanthridine skeleton and the vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton are constructed stereospecifically in one step employing intramolecular 1,3-dipolar cyclo addition of a nonstabilized azomethine ylide (AMY) generated by the sequential double desilylation of appropriate bis-trimethylsilylmethyl amines using Ag(I)F as a single-electron oxidant. The strategy is successfully applied for the total synthesis of biologically active alkaloids such as (+/-)-pancracine, (+/-)-brunsvigine, (+/-)-maritidine, and (+/-)-crinine.</p>10aalkaloid synthesis10acycloadditions10aorganic synthesis10astereocontrolled synthesis1 aPandey, Ganesh1 aGadre, Smita, R.  uhttps://library.ncl.res.in/content/stereoselective-construction-511-methanomorphanthridine-and-510b-phenanthridine-structural-0