title: Total Synthesis of the Antitumor Macrolides, (+)-Brefeldin A and 4-Epi-Brefeldin A from d-Glucose: Use of the Padwa Anionic Allenylsulfone [3 + 2]-Cycloadditive Elimination To Construct Trans-Configured Chiral Cyclopentane Systems.
abstract: A new synthesis of (+)-brefeldin A is reported via Padwa allenylsulfone [3 + 2]-cycloadditive elimination. Cycloadduct 13 was initially elaborated into iodide 27, which, following treatment with Zn, gave aldehyde 28 whose C(9) stereocenter was epimerized. Further elaboration into enoate 38 and Julia-Kocienski olefination with 5 subsequently afforded 39, which was deprotected at C(1) and O(15). Yamaguchi macrolactonization of the seco-acid thereafter afforded a macrocycle that underwent O-desilylation and inversion at C(4) to give (+)-brefeldin A following deprotection.
authors.affiliation: The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen's University Belfast , Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom.
authors.forename: Ziyue
authors.initials: Z
authors.lastname: Xiong
authors.affiliation: The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen's University Belfast , Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom.
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Hale