52978-85-5Relevant articles and documents
Reaction of 2-(Ethoxycarbonyl)pentadienylsilane under Ritter Condition. Formation of α-Methylene-γ-lactone by Self-cyclization
Kuroda, Chiaki,Mitsumata, Naoko
, p. 1375 - 1378 (1994)
An acylative C(3)-C(4)-bond cleavage of 4,5-disubstituted 2-trimethylsilylmethyl-penta-2,4-dienoate occurred by treatment with trifluoromethanesulfonic acid in nitriles, while a self-cyclization giving an α-methylene-γ-lactone also occurred when the reactions were carried out in bulky nitriles.
Strain-Driven Dyotropic Rearrangement: A Unified Ring-Expansion Approach to α-Methylene-γ-butyrolactones
Lei, Xiaoqiang,Li, Yuanhe,Lai, Yang,Hu, Shengkun,Qi, Chen,Wang, Gelin,Tang, Yefeng
supporting information, p. 4221 - 4230 (2020/12/22)
An unprecedented strain-driven dyotropic rearrangement of α-methylene-β-lactones has been realized, which enables the efficient access of a wide range of α-methylene-γ-butyrolactones displaying remarkable structural diversity. Several appealing features of the reaction, including excellent efficiency, high stereospecificity, predictable chemoselectivity and broad substrate scope, render it a powerful tool for the synthesis of MBL-containing molecules of either natural or synthetic origin. Both experimental and computational evidences suggest that the new variant of dyotropic rearrangements proceed in a dualistic pattern: while an asynchronous concerted mechanism most likely accounts for the reactions featuring hydrogen migration, a stepwise process involving a phenonium ion intermediate is favored in the cases of aryl migration. The great synthetic potential of the title reaction is exemplified by its application to the efficient construction of several natural products and relevant scaffolds.
Ruthenium-Catalyzed Cyclocarbonylation of Allenyl Alcohols and Amines: Selective Synthesis of Lactones and Lactams
Yoneda, Eiji,Zhang, Shi-Wei,Zhou, Da-Yang,Onitsuka, Kiyotaka,Takahashi, Shigetoshi
, p. 8571 - 8576 (2007/10/03)
Allenyl alcohols such as 4-hydroxybuta-1,2-dienes and 5-hydroxypenta-1,2-dienes having a variety of substituents undergo cyclocarbonylation in the presence of a ruthenium catalyst under mild conditions selectively to give five- and six-membered lactones in a high yield with 100% atom economy. 5-Aminopenta-1,2-dines are also cyclocarbonylated to give γ-lactams. A possible carbonylation mechanism involving a ruthenium cluster intermediate is proposed on the basis of experimental results.
Indium-promoted preparation of substituted α-methylene-γ-lactones from 2-(bromomethyl)acrylic acid and carbonyl compounds
Choudhury, Prabir K.,Foubelo, Francisco,Yus, Miguel
, p. 3581 - 3584 (2007/10/03)
The reaction of 2-(bromomethyl)acrylic acid (1) with different carbonyl compounds (2) [CH20, (E)-CH3CH=CHCHO, Pr(i)CHO, Bu(t)CHO, PhCHO, CH3(CH2)5CHO, c-C6H11CHO, Ph2CHCHO, (CH2)5CO] and indium powder in a 1:1 THF:H20 mixture at room temperature affords, after acidic work-up with hydrochloric acid, the corresponding α-methylene-γ-butyrolactones 3.
