Formal synthesis of (+)-neooxazolomycin via a Stille cross-coupling/deconjugation route
摘要:
A formal synthesis of neooxazolomycin is described via the preparation of Kende's key intermediate in a longest linear sequence of 23 steps. This work is founded upon the union of three fragments: Moloney's lactam-derived triflate, a vinyl stannane and a Julia-Kocienski sulfone and encompasses three key steps: (i) a Stille cross-coupling to combine the triflate and vinyl stannane, (ii) a base-promoted enone deconjugation to derive the dihydroxylation precursor and (iii) our previously reported Julia-Kocienski methodology to assemble the pentadienyl amine side chain with the sulfone precursor. (C) 2011 Elsevier Ltd. All rights reserved.
Enantiomerically Pure Synthetic Building Blocks with Four C-Atoms and Two or Three Functional Groups from β-Hydroxy-butanoic, Malic, and Tartaric Acid
具有四个C原子和两个或三个来自β-羟基丁酸,苹果酸和酒石酸的官能团的对映体纯合成构件
Gram scale synthesis of the C(1)–C(9) fragment of amphidinolide C
作者:Nicholas A. Morra、Brian L. Pagenkopf
DOI:10.1016/j.tet.2013.07.026
日期:2013.10
Subsequent manipulations, including a Still–Gennari olefination, Sharpless asymmetric dihydroxylation, Corey–Fuchs alkynylation, and Kazmaier hydrostannylation provided the fully functionalized C(1)–C(9) fragment 2 suitable for cross-coupling. The sequence is readily scalable and provides gram quantities of 2.
Divergent Reactivity via Cobalt Catalysis: An Epoxide Olefination
作者:Megan L. Jamieson、Paul A. Hume、Daniel P. Furkert、Margaret A. Brimble
DOI:10.1021/acs.orglett.5b03514
日期:2016.2.5
Cobaltsalts exert an unexpected and profound influence on the reactivity of epoxides with dimethylsulfoxonium methylide. In the presence of a cobalt catalyst, conditions for epoxide to an oxetane ring expansion instead deliver homoallylic alcohol products, corresponding to a two-carbon epoxide homologation/ring-opening tandem process. The observed reactivity change appears to be specifically due to