title: Total synthesis of (-)-brevenal: a streamlined strategy for practical synthesis of polycyclic ethers.
abstract: We describe a streamlined strategy for the practical synthesis of trans-fused polycyclic ethers and its application to a concise total synthesis of (-)-brevenal, a new pentacyclic polyether natural product with intriguing biological activities. The B-, D-, and E-rings were constructed by TEMPO/PhI(OAc)(2)-mediated oxidative lactonization of the corresponding 1,6-diols, with minimal need for manipulation of oxygen functionalities. The B- and E-ring lactones were appropriately functionalized by Suzuki-Miyaura coupling of lactone-derived enol phosphates and subsequent stereoselective hydroboration. The A-ring was formed by our mixed thioacetalization methodology. The AB- and DE-ring fragments were assembled through Suzuki-Miyaura coupling, and the C-ring was forged in the same manner as that for the A-ring. More than two grams of the pentacyclic polyether core of (-)-brevenal have been synthesized by the synthetic route developed in this study.
authors: Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors: Makoto
authors: M
authors: Ebine
authors: Haruhiko
authors: H
authors: Fuwa
authors: Makoto
authors: M
authors: Sasaki
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D004141:Dinoflagellida / Q000737:chemistry; D004987:Ethers / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001688:Biological Products; D004987:Ethers; D011108:Polymers; C489035:brevenal (polyether)