Synthesis and claisen rearrangement of 1-allyloxy-1-carbomethoxy allenes
TL;DR: A number of allyl allenyl ethers (1) have been synthesised and shown to undergo the Claisen rearrangement as discussed by the authors, which is consistent with a concerted mechanism for these rearrangements.
About: This article is published in Tetrahedron Letters.The article was published on 1989-01-01. It has received 21 citations till now. The article focuses on the topics: Carroll rearrangement & Sigmatropic reaction.
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76 citations
TL;DR: In this paper, the dependence of the regioselectivity of the allenyl enolate intermediate on the protonating agent is studied: pure allenes are obtained by quenching the intermediate with pivalic acid at −80°C.
Abstract: Ten β-allenic esters, ketones, and thioesters 15 bearing alkyl, alkenyl, aryl, and trimethylsilyl groups are synthesized in 57- 85% yield by 1,6-addition of organocuprates to polarized enynes 10. The dependence of the regioselectivity of the protonation of the allenyl enolate intermediate 7 on the protonating agent is studied: pure allenes are obtained by quenching the intermediate with pivalic acid at −80°C. The method is applied in a short synthesis of pseudoionone (18).
49 citations
TL;DR: This highly efficient process proceeds under mild conditions, tolerates various functional groups, and generally provides substituted 2(3H)-furanones in good to excellent yields.
Abstract: A variety of highly substituted 2(3H)-furanones are readily prepared from 3-alkynoate esters and the corresponding acids via electrophilic cyclization. Successful electrophiles in this process include I2, ICl, and PhSeCl. This highly efficient process proceeds under mild conditions, tolerates various functional groups, and generally provides substituted 2(3H)-furanones in good to excellent yields.
47 citations
TL;DR: Optically active 4,4-disubstituted conjugated allenecarboxylates were enantioselectively prepared via CC bond formation through an asymmetric Horner-Wadsworth-Emmons reaction with an optically active phosphonoacetate reagent as mentioned in this paper.
42 citations
TL;DR: Inspired by this development, substituent and solvent rate effects are studied, and evidence that a chairlike transition state is highly favorable for the uncatalyzed Gosteli-Claisen rearrangement is provided.
Abstract: The results of kinetic studies on the uncatalyzed [3,3]-sigmatropic rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ethers are reported. Apparently first reported by Gosteli in 1972, this variation of a Claisen rearrangement enjoyed a shadowy existence for three decades until its potential for the development of a catalytic asymmetric Claisen rearrangement was discovered. Inspired by this development, we have studied substituent and solvent rate effects, and we provide evidence that a chairlike transition state is highly favorable for the uncatalyzed Gosteli-Claisen rearrangement.
37 citations
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TL;DR: The utility of tert-butyldiphenylsilyl chloride as a reagent for the protection of hydroxyl groups was explored in this article, where the corresponding tert-BDPSi ethers have much greater stability to acids, and under...
Abstract: The utility of tert-butyldiphenylsilyl chloride as a reagent for the protection of hydroxyl groups was explored. The corresponding tert-BDPSi ethers have much greater stability to acids, and under ...
414 citations
TL;DR: Suicide substrates are defined as a class of irreversible inactivators of specific target enzymes where the target enzyme participates in its own destruction by catalytic unmasking of a latent functional group at some stage in the catalytic cycle of the enzyme.
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