Lithium- α-lithioacetate and β-lithiopropionate: useful intermediates in organic synthesis
作者:Isidro M Pastor、Miguel Yus
DOI:10.1016/s0040-4039(00)00794-2
日期:2000.7
The reaction of chloroacetic acid and 3-chloropropionic acid with a base (LDA or BunLi, respectively) and then with an excess of lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5%) in the presence of different electrophiles [ButCHO, PhCHO, Et2CO, (CH2)5CO, PhCOMe] in THF at −78°C leads, after hydrolysis with water, to the expected hydroxy acids, which in the second case are directly
氯乙酸和3-氯丙酸与碱(分别为LDA或Bu n Li)的反应,然后与过量的锂和催化量的4,4'-二叔丁基联苯(DTBB,5%)反应在不同的亲电子试剂的存在下[卜吨CHO,苯甲醛,等2 CO,(CH 2)5 CO,PhCOMe]在THF中在-78℃下引线,与水水解后,与预期的羟基酸,其中在所述第二在酸性条件下,直接将其环化,得到预期的γ-内酯。
Regioselective Synthesis of γ-Lactones by Iron-Catalyzed Radical Annulation of Alkenes with α-Halocarboxylic Acids and Their Derivatives
An abundant and low toxicity iron catalyst has enabled regioselective annulation of alkenes with α-halocarboxylic acids and their derivatives. The reaction proceeds smoothly without any additional ligands, bases, and additives to afford a variety of γ-lactones in good yields. A proposed reaction pathway through radical annulation is supported by some mechanistic studies, involving radical clock and
Cu-catalyzed intermolecular oxyalkylation of styrenes under air: access to diverse iminolactones
作者:Yunhe Lv、Weiya Pu、Shukuan Mao、Xiaoran Ren、Yingtao Wu、Hao Cui
DOI:10.1039/c7ra07306b
日期:——
A practical, simple, and efficient copper-catalyzed oxyalkylation of styrenes with α-bromoacetamides for the synthesis of iminolactones was developed under air.
A newsynthesis of γ-lactones by peroxydisulfate oxidation of isopropylbenzenes is described. Evidence concerning the free-radical mechanism is reported; the intermediate formation of alkyl and benzyl radicals is evidenced by trapping them with quinoxaline. The role of the iron catalyst is discussed.