A new photochemical synthesis of cyclopropanecarboxylic acids present in pyrethroids by the aza-di-π-methane rearrangement
作者:Diego Armesto、Mar G. Gallego、William M. Horspool、Antonia R. Agarrabeitia
DOI:10.1016/0040-4020(95)00527-f
日期:1995.8
A novel synthetic route to chrysanthemic acid, 2-cyclopentylidenmethyl-3,3-dimethylcyclopropanecarboxylic acid, fluorenespiro-2,2-dimethylcyclopropanecarboxylic acid and indenespiro-2,2-dimethylcyclopropanecarboxylic acid, all of them present in pyrethroids of known insecticidal activity, is described. The key step in the synthesis is the aza-di-n-rnethane rearrangement of some 1-aza-1,4,6-trienes
Remarkable Observations on Triplet-Sensitized Reactions. The Di-π-methane Rearrangement of Acyclic 1,4-Dienes in the Triplet Excited State
作者:Diego Armesto、Maria J. Ortiz、Antonia R. Agarrabeitia、Mar Martin-Fontecha、Noureddin El-Boulifi、Gonzalo Duran-Sampedro、Danielle Enma
DOI:10.1021/ol901636z
日期:2009.9.17
large majority of acyclic 1,4-dienes do not undergo photochemical di-π-methane (DPM) rearrangement under triplet-sensitized irradiation. The results of a detailed analysis of these processes demonstrate that a series of these compounds do indeed undergo highly efficient DPM rearrangement from their triplet excited states when suitable triplet sensitizers are used.
The photochemical synthesis of potential pyrethroid components by the aza-di-π-methane rearrangement of β,γ-unsaturated oxime acetates.
作者:Diego Armesto、Mar G. Gallego、William M. Horspool
DOI:10.1016/s0040-4039(00)97393-3
日期:1990.1
The syntheses and photochemical reactions of oxime acetates of ethyl 4,4-dimethyl-5-oxopent-2-enoate and ethyl 2,4,4-trimethyl-5-oxo-2-enoate are described. The former compound undergoes EZ of the CC bond while the latter rearranges by the aza-di-π-methane reaction to afford a cyclopropane derivative.
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).
SmI2-Mediated 3-exo-trig cyclisation of δ-oxo-α,β-unsaturated esters to cyclopropanols and derivatives
In the presence of samarium diiodide and a proton source, delta-oxo-gamma,gamma-disubstituted-alpha,beta-unsaturated esters of general formula R-CO-C(R',R')-CH=CH-CO2Bn readily cyclise to trans-cyclopropanol products and/or lactones derived from the cis isomers. For R=aryl, good stereoselectivities (ca 90%) in favor of the alcohols are generally obtained while a mixture of alcohols and lactones is obtained with R=alkyl or H. For R=cyclopropyl, the lactone is exclusively obtained in more than 90% yield. A mechanistic rationalisation of these variations of diastereoselectivity is proposed. (C) 2004 Elsevier Ltd. All rights reserved.