[EN] SYNTHESIS OF PELORUSIDE A AND ANALOGS THEREOF FOR USE AS ANTITUMOR AGENTS [FR] SYNTHESE DU PELORUSIDE A ET ANALOGUES DE CELUI-CI POUVANT ETRE UTILISES EN TANT QU'AGENTS ANTITUMORAUX
Total Synthesis of Peloruside A through Kinetic Lactonization and Relay Ring-Closing Metathesis Cyclization Reactions
作者:Thomas R. Hoye、Junha Jeon、Lucas C. Kopel、Troy D. Ryba、Manomi A. Tennakoon、Yini Wang
DOI:10.1002/anie.201002293
日期:2010.8.16
The other side: A convergent totalsynthesis of peloruside A (1) is described. The key strategic features are a diastereoselective lactonization to generate a C5–C9 valerolactone from the C2‐symmetric ketone 3, and a relay ring‐closing metathesis reaction to produce a dehydrovalerolactone 2. A new isomer of 1, the valerolactone isopeloruside A (iso‐1), was identified. MOM=methoxymethyl.
An improved synthesis of Kagan’s menthyl substituted titanocene and zirconocene dichloride, comparison of their crystal structures, and preliminary catalyst evaluation
An improved synthesis of 1 and 2 is described that allows access to these complexes in multigram quantities necessary for catalytic applications. The crystal structures of 1 and 2 are compared and the conformational preferences of the ligands, that are important for catalytic applications, are discussed. Complex 2 was evaluated as a catalyst for carbomagnesation reactions.
terminal alkenes catalysed by (R,R)-ethylene-1,2-bis(η5-4,5,6,7-tetrahydro-1-indenyl)zirconium(R)-1,1′-binaphth-2,2′-diolate gave low turnovers and enantioexcesses. A novel Ci symmetric zirconocene dichloride CpCp′ZrCl2 (Cp = C5H5, Cp′ = 1-neomenthyl-4,5,6,7-tetrahydroindenyl) was prepared which gave better enantioselectivity, is cheaper to make, catalytically more active, and recoverable.
通过催化末端烯烃的ethylmagnesiation([R ,- [R )-亚乙基-1,2-双(η 5 -4,5,6,7-四氢-1-茚基)合锆([R)-1,1'- binaphth- 2,2'-羟乙酸盐产生较低的营业额和对映体过量。制备了一种新的C i对称的二茂锆锆CpCp'ZrCl 2(Cp = C 5 H 5,Cp'= 1-新薄荷基-4,5,6,7-四氢茚基),该对映体具有更好的对映选择性,制造成本更低,催化作用更多。活跃且可恢复。
Enantioselective Synthesis of α-Alkyl-β,γ-unsaturated Esters through Efficient Cu-Catalyzed Allylic Alkylations
作者:Kerry E. Murphy、Amir H. Hoveyda
DOI:10.1021/ja0300618
日期:2003.4.1
A method for enantioselective Cu-catalyzed allylic substitution between various alkylzincs and alpha,beta-unsaturated carboxylic esters that bear a gamma-phosphate is reported. These transformations afford alpha-alkyl-beta,gamma-unsaturated carbonyls with regioselectivities of 7:1 to >20:1 (S(N)2':S(N)2) and in 87-97% ee. The utility of the method is illustrated by a convergent total synthesis of topoisomerse II inhibitor (R)-elenic acid.
Total Synthesis of (−)-2-<i>epi</i>-Peloruside A
作者:Amos B. Smith、Jason M. Cox、Noriyuki Furuichi、Craig S. Kenesky、Junying Zheng、Onur Atasoylu、William M. Wuest
DOI:10.1021/ol8019132
日期:2008.12.18
A convergent synthesis of (-)-2-epi-peloruside A has been achieved. Highlights include implementation of multicomponent type I anion relay chemistry (ARC) to unite 2-TBS-1,3-dithiane with two epoxides to construct the eastern hemisphere, a late-stage dithiane union to secure the complete, fully functionalized carbon backbone, and Yamaguchi macrolactonization, which led to (-)-2-epi-peloruside A via an unexpected epimerization at C(2).