Racemic synthesis of 1,2-secomicrominutinin

Abstract

A 1,2-secomicrominutinina (25) racêmica foi sintetizada empregando-se a reação de cicloadição intramolecular de um alceniloxiceteno, preparado a partir do correspondente tosilato. O alceniloxiceteno sofre reação de cicloadição [2+2] intramolecular originando uma benzociclobutafuranona tricíclica (16) que, por oxidação de Bayer-Villiger, fornece uma benzofurofuranona (17). Reação desta última com propiolato de metila, catalisada por trifenilfosfina, produziu o derivado de éster cinâmico (25).The racemic 1,2-secomicrominutinin (25) was synthesized employing the intramolecular cycloaddition reaction of an (alkenyloxy)ketene, prepared from the corresponding tosylate. The (alkenyloxy)ketene undergoes intramolecular [2+2] cycloaddition to give tricyclic benzocyclobutafuranone (16), which by Baeyer-Villiger oxidation gives a benzofuranofuranone (17). Reaction of the latter compound with methyl propiolate, catalyzed by triphenylphosphine, produced the cinnamic ester derivative (25).

Total Synthesis and Biological Evaluation of (−)-Apicularen A and Its Analogues

“…Syntheses of the fragments 12 and 13 are outlined in Schemes and , respectively. The synthesis of 12 began with triflate 14 , which was derived from commercially available methyl 2,6-dihydroxybenzoate. The Stille coupling of 14 with allyltributyltin in the presence of Pd-catalyst gave alkene 15 in 90% yield.…”

Total Synthesis of (−)-Apicularen A

“…In the synthesis of aromatic fragment 8 (Scheme ), the Stille coupling of 10 with allyltributyltin in the presence of cat. [Pd(PPh 3 ) 4 ] gave terminal alkene 11 in 90% yield.…”