01154nas a2200169   4500008004100000022001400041245013300055210006900188260000900257300001200266490000700278520050200285100002200787700002200809700002200831856013100853       2018                        eng d  a1523-706000aSynthesis of furo[2,3-b]pyran-2-ones through Ag(I)- or Ag(I)-Au(I)-catalyzed cascade annulation of alkynols and alpha-ketoesters0 aSynthesis of furo23bpyran2ones through AgI or AgIAuIcatalyzed ca  cFEB   a872-8750 v203 a<p>Ag(I)- or Ag(I)-Au(I)-catalyzed cascade annulation of alkynols (5-hexyn-1-ol systems) with a-ketoesters involving a dual activation process (pi and sigma) has been developed for the first time. This reaction proceeds through cycloisomerization of alkynol to give the 6-endo-enol ether followed by annulation with an alpha-ketoester to furnish furo[2,3-b]pyran-2-ones in good yields. Chemical structures of all products were rigorously confirmed by single crystal X-ray analysis and analogy.</p>1 aThorat, Sagar, S.1 aKataria, Priyanka1 aKontham, Ravindar  uhttps://library.ncl.res.in/content/synthesis-furo23-bpyran-2-ones-through-agi-or-agi-aui-catalyzed-cascade-annulation-alkynols01452nas a2200169   4500008004100000022001400041245013100055210006900186260000900255300001200264490000700276520080400283100002201087700001901109700002201128856013201150       2022                        eng d  a1477-052000aStudies directed toward the synthesis of hedycoropyrans: total synthesis of des-hydroxy (-)-hedycoropyran B (ent-rhoiptelol B)0 aStudies directed toward the synthesis of hedycoropyrans total sy  cJAN   a444-4630 v203 aA full account of our efforts directed towards the synthesis of the diarylheptanoid-derived natural products hedycoropyrans that led to the total synthesis of ent-rhoiptelol B is described. In this endeavor, we have attempted two distinct synthetic strategies to access hedycoropyrans A and B, which led us to establish a facile synthetic route for des-hydroxy (-)-hedycoropyran B (ent-rhoiptelol B) from simple and readily accessible building blocks of 4-allylanisole and vanillin, employing Sharpless asymmetric epoxidation, CBS reduction, and an intramolecular AgOTf-catalyzed oxa-Michael reaction of suitably functionalized hydroxy-ynone as key transformations. The investigations disclosed herein will provide insights into designing novel synthetic routes for THP-DAH-derived natural products.1 aKataria, Priyanka1 aNomula, Rajesh1 aKontham, Ravindar  uhttps://library.ncl.res.in/content/studies-directed-toward-synthesis-hedycoropyrans-total-synthesis-des-hydroxy-hedycoropyran-b