01312nas a2200193   4500008004100000022001400041245016900055210006900224260000900293300001400302490000700316520055000323100002400873700002300897700002200920700002500942700002400967856012700991       2021                        eng d  a0022-326300aFormal synthesis of (-)-quinagolide: diastereoselective ring expansion via a bicyclic aziridinium ion strategy to access the octahydrobenzo[g]quinoline architecture0 aFormal synthesis of quinagolide diastereoselective ring expansio  cJUL   a9344-93520 v863 aThe diastereoselective formal synthesis of (-)-quinagolide, a D-2 receptor agonist, has been achieved. The synthesis started from L-pyroglutamic acid and relied on utilization of (a) a stereospecific catalytic hydrogenation and diastereoselective Horner-Emmons-Michael cascade to obtain functionalized prolinate, (b) a Lewis acid mediated Pummerer cyclization to construct a tricyclic fused ring system, and (c) a diastereoselective ring expansion via a bicyclic aziridinium intermediate to access the required 3-substituted piperidine scaffold.1 aChavan, Subhash, P.1 aKawale, Sanket, A.1 aPisal, Mahesh, M.1 aKadam, Appasaheb, L.1 aGonnade, Rajesh, G.  uhttps://library.ncl.res.in/content/formal-synthesis-quinagolide-diastereoselective-ring-expansion-bicyclic-aziridinium-ion