01308nas a2200181 4500008004100000022001400041245009500055210006900150260007100219300001400290490000700304520059800311100001900909700002600928700002500954700002300979856012401002 2008 eng d a0022-326300aTotal synthesis and determination of relative and absolute configuration of multiplolide A0 aTotal synthesis and determination of relative and absolute confi a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a3817-38220 v733 a

A flexible approach for total syntheses of possible multiplolide A diastereomers establishing the relative and absolute configuration is documented. The adopted strategy features ring-closing metathesis (RCM) as the key reaction and screening of a set of substrates for the feasibility of RCM in general and for the requisite E-configuration of ring olefin in particular. Selective protecting groups manipulation prior to the assembly of the central macrocyclic core was instrumental in installing the epoxide functionality on a fully deprotected nonenolide at the end of the synthesis.

1 aRamana, C., V.1 aKhaladkar, Tushar, P.1 aChatterjee, Soumitra1 aGurjar, Mukund, K. uhttps://library.ncl.res.in/content/total-synthesis-and-determination-relative-and-absolute-configuration-multiplolide-001258nas a2200181 4500008004100000022001400041245013700055210006900192260011000261300001200371490000700383520046000390100001900850700002500869700002900894700002400923856012900947 2009 eng d a1466-803300aClick synthesis of isomeric compounds for assessing the efficiency of the bifurcated Br center dot center dot center dot NO2 synthon0 aClick synthesis of isomeric compounds for assessing the efficien aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT a143-1500 v113 a

We report herein the extention of the azide-alkyne ``click reaction'' to crystal engineering and synthesize a collection of isomeric compounds with modular positioning of Br and NO2 on a tricyclic template and crystal structural analyses of the derived isomers. It is quite remarkable to notice that none of the isomers displayed the bifurcated three-center NO2 center dot center dot center dot Br supramolecular synthon in their crystal structures

1 aRamana, C., V.1 aChatterjee, Soumitra1 aDurugkar, Kulbhushan, A.1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/click-synthesis-isomeric-compounds-assessing-efficiency-bifurcated-br-center-dot-center-002001nas a2200193 4500008004100000245021400041210006900255260000800324300001400332490000700346520115000353100002401503700001901527700002901546700002501575700002701600700002401627856015601651 2013 eng d00aEvaluation of viability of halogen•••O2N interactions: insight form crystal packing in a series of isomeric halo and nitro substituted triaryl compounds with modular positioning of halogen and NO2 groups0 aEvaluation of viability of halogen O2N interactions insight form cAPR a5283-53000 v153 a

A series of isomeric triaryl compounds with a modular positioning of the halogen and NO2 groups have been synthesized by the azide–alkyne “click reaction” and have been characterized by single crystal X-ray structure analysis. This isomeric series has provided an opportunity for understanding the efficiency of the bifurcated halogen⋯NO2 synthon in the organization of the molecules in the crystalline lattice. The changes in molecular conformation, crystal packing and supramolecular aggregation due to the change in the relative positioning of the complementary groups, halogen atom and the NO2 group on ring A and ring C respectively, have been discussed. All the isomers synthesized are crystalline and establish the triazole as a reliable linker for crystal engineering oriented molecular synthesis. The 2-NO2 derivatives display in general, a helical architecture and 3-NO2 derivatives exhibit a centrosymmetric dimeric assembly via the complementary C–H⋯O interactions leading to either a helical or a 2-dimensional sheet pattern. The molecular organization in 4-NO2 derivatives revealed in general a 2D sheet pattern.

1 aRamana, Chepuri, V.1 aGoriya, Yogesh1 aDurugkar, Kulbhushan, A.1 aChatterjee, Soumitra1 aKrishnaswamy, Shobhana1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/evaluation-viability-halogen%E2%80%A2%E2%80%A2%E2%80%A2o2n-interactions-insight-form-crystal-packing-series-isomeric