4541-32-6Relevant articles and documents
Stereochemical Effects in the Gas-Phase Pinacol Rearrangement of cis- and trans-1,2-Dimethylcyclopentane-1,2-diol
Petris, Giulia de,Giacomello, Pierluigi,Picotti, Tito,Pizzabiocca, Adriano,Renzi, Gabriele,Speranza, Maurizio
, p. 7491 - 7495 (1986)
The pinacol rearrangement of cis- and trans-1,2-dimethylcyclopentane-1,2-diol, promoted by the gaseous Broensted acids D3+, CH5+/C2H5+, and t-C4H9+, was studied by mass spectrometric and radiolytic methods.Dehydration of the protonated substrate is rate limiting, and competitive experiments with pinacol, carried out at high pressure (760 torr), showed that the cis rearranges more rapidly than the trans isomer, indicating participation of the migrating methyl group to the leaving water molecule.The results are compared with those concerning the same substrates in solution, where no evidence of anchimeric assistance was found.
Preparation method of 2, 2-dimethyl cyclopentanone
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Paragraph 0022, (2021/06/23)
The invention discloses a preparation method of 2, 2-dimethyl cyclopentanone, which comprises the following steps: methylating 2-methoxycarbonyl cyclopentanone to obtain a methylated product 2-methyl-2-methoxycarbonyl cyclopentanone, carrying out keto-carbonyl protection on the methylated product to obtain a protected product 2-methyl-2-methoxycarbonyl cyclopentanone ketal, carrying out ester group reduction on the protection product to obtain an alcohol product 2-hydroxymethyl-2-methyl cyclopentanone ketal, carrying out deprotection on the alcohol product under an acidic condition to obtain a deprotection product 2-hydroxymethyl-2-methyl cyclopentanone, and brominating the deprotection product to obtain 2-bromomethyl-2-methyl cyclopentanone. All raw materials adopted by the method are low in cost and easy to obtain in the market, and reactions in all steps are conventional reactions and easy to implement; the process is simple, mild in reaction condition and easy to operate; the reaction time is short, control is easy, the yield of each step is 90% or above, and industrial large-scale production is easy to achieve.
Organozinc-aided, HMPA-free, stoichiometric three-component coupling for the general synthesis of prostaglandins and stable prostacyclin analogs with biological significance
Koyama, Hiroko,Izumiseki, Atsuto,Suzuki, Masaaki
, p. 1467 - 1470 (2019/05/07)
A three-component coupling procedure was developed to construct the entire prostaglandin (PG) skeleton under HMPA-free and stoichiometric conditions via a combination of dimethylzinc-aided conjugate addition of an ω-side-chain vinyllithium with (R)-4-hydroxy-2-cyclopentenone and the direct trapping of the resulting enolate with an α-side-chain propargyl triflate. Dimethylzinc effectively regulated both the conjugate addition and alkynylation reactions. Thus, the method afforded protected 5,6-didehydro-PGE2, a common intermediate for the general synthesis of natural PGs and the stable artificial prostacyclin (PGI2) analog isocarbacyclin in 88% yield. The utility of the method was further applied to the syntheses of novel intermediates, which are useful for the straightforward synthesis of 15R-TIC and 15-deoxy-TIC in 79% and 86% yield, respectively.
SUBSTITUTED HETEROCYCLIC AMINE COMPOUNDS AS CHOLESTRYL ESTER-TRANSFER PROTEIN (CETP) INHIBITORS
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Page/Page column 24; 25, (2013/03/26)
The present application relates to cycloalkylpyridin-2-amines derivates of formula (I) or stereoisomers thereof or pharmaceutically acceptable salts thereof. The present application also relates to the process for the preparation of compounds of formula (I). The present application further describes the compounds of formulat (I) as cholesteryl ester-transfer protein (CETP) inhibitors. The present application further relates to pharmaceutical compositions comprising compounds of formula (I) or stereoisomers thereof or pharmaceutically acceptable salts thereof.
