01546nas a2200217   4500008004100000022001400041245009100055210006900146260007500215300001400290520072600304653002501030653003401055653001601089653001501105653002101120100002401141700001901165700001901184856012501203       2016                        eng d  a1434-193X00aEnantioselective modular total synthesis of macrolides Sch725674 and C-4-epi-Sch7256740 aEnantioselective modular total synthesis of macrolides Sch725674  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB  a1215-12263 a<p>The convergent total synthesis of Sch725674 has been accomplished by starting from (R)-1,2-epoxyheptane and assembling five modules in a highly stereoselective manner to give the final product in 6.6% overall yield. The same strategy was extended to the synthesis of its C-4 epimer. Key reactions of the synthetic pathway include a Jacobsen hydrolytic kinetic resolution of an epoxide followed by its regioselective opening through a Yamaguchi-Hirao alkynylation, and ring-closing metathesis reaction to furnish the unique 14-membered ring macrolactone. In addition, the influence of protecting groups on the efficiency of the ring-closing metathesis (RCM) macrocyclization has been studied to maximize its yields.</p>10aAsymmetric synthesis10aHydrolytic kinetic resolution10aMacrocycles10aMetathesis10aNatural products1 aSharma, Brijesh, M.1 aGontala, Arjun1 aKumar, Pradeep  uhttps://library.ncl.res.in/content/enantioselective-modular-total-synthesis-macrolides-sch725674-and-c-4-epi-sch725674-0