01388nas a2200241   4500008004100000022001400041245010900055210006900164260010600233300001400339490000700353520048700360653002200847653002300869653001500892653001400907653001500921100001900936700001700955700002400972700002300996856012701019       2006                        eng d  a0040-403900aPalladium mediated cycloisomerization of sugar alkynols: synthesis of cyclic enol-ethers and spiroketals0 aPalladium mediated cycloisomerization of sugar alkynols synthesi  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a3649-36520 v473 a<p>Functionalized bicyclic enol-ethers and spiroketals are prepared by Pd catalyzed cycloisomerization of 3-C-alkynylfuranosyl derivatives. Cycloisomerization of differently substituted alkyne derivatives revealed a preference for 6-endo-dig cyclization over 5-exo-dig if the substituent is not sufficiently electron withdrawing. The scope of these cycloisomerizations has been further extended by integrating with conjugate addition. (c) 2006 Elsevier Ltd. All rights reserved.</p>10ac-alkynylfuranose10acycloisomerization10aenol-ether10aPalladium10aSpiroketal1 aRamana, C., V.1 aMallik, Rosy1 aGonnade, Rajesh, G.1 aGurjar, Mukund, K.  uhttps://library.ncl.res.in/content/palladium-mediated-cycloisomerization-sugar-alkynols-synthesis-cyclic-enol-ethers-and-001424nas a2200229   4500008004100000022001400041245017900055210006900234260010600303300001200409490000700421520049700428653002300925653002300948653001500971653001400986653001501000100001901015700001701034700002401051856011901075       2008                        eng d  a0040-402000aInfluence of electronic factors on palladium-mediated cycloisomerization: a systematic investigation of competitive 5-exo-dig versus 6-endo-dig cyclizations of sugar alkynols0 aInfluence of electronic factors on palladiummediated cycloisomer  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJAN  a219-2330 v643 a<p>Pd-mediated cycloisomerization of 3-C-alkynyl-allo- and ribofuranose derivatives was investigated in detail to understand the influence of electronic factors on the regioselectivity in ring closure reaction. The reactions in general are influenced by the electronic nature of the substituent on the alkyne unit. A preference for endo-dig cyclization over exo-dig is noted, if the alkynyl substituent is not sufficiently electron withdrawing, (c) 2007 Elsevier Ltd. All rights reserved.</p>10aC-alkynyl furanose10acycloisomerization10aenol ether10aPalladium10aSpiroketal1 aRamana, C., V.1 aMallik, Rosy1 aGonnade, Rajesh, G.  uhttps://library.ncl.res.in/content/influence-electronic-factors-palladium-mediated-cycloisomerization-systematic-001324nas a2200217   4500008004100000022001400041245009000055210006900145260010600214300001000320490000700330520048900337653002100826653003100847653003400878653001400912653001500926100002300941700002200964856012000986       2016                        eng d  a0040-403900aFormal total synthesis of anti-helicobacter pylori agent (+)-spirolaxine methyl ether0 aFormal total synthesis of antihelicobacter pylori agent spirolax  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJAN  a25-280 v573 a<p>A convergent, formal enantioselective synthesis of anti-Helicobacter pylori agent, (+)-spirolaxine methyl ether 2 has been achieved in high enantiomeric purity starting from commercially available 1,5-pentanediol. The strategy mainly comprises of the Noyori's asymmetric reduction and Brown allylation/Cu-catalyzed lactonization as the key step for the construction of key chiral intermediates, spiroketal 3 and phthalide fragment 4. (C) 2015 Elsevier Ltd. All rights reserved.</p>10aBrown allylation10aCu-catalyzed lactonization10aNoyori's asymmetric reduction10aPhthalide10aSpiroketal1 aGadakh, Sunita, K.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/formal-total-synthesis-anti-helicobacter-pylori-agent-spirolaxine-methyl-ether-0