100573-56-6Relevant academic research and scientific papers
The direct and highly diastereoselective synthesis of 3,4-epoxy-2-piperidones. Application to the total synthesis and absolute configurational assignment of 3α,4α-epoxy-5β-pipermethystine
Osorio-Nieto, Urbano,Vázquez-Amaya, Laura Y.,H?pfl, Herbert,Quintero, Leticia,Sartillo-Piscil, Fernando
, p. 77 - 88 (2017)
The substrate-controlled asymmetric total synthesis and absolute configurational assignment of biologically active 3α,4α-epoxy-5β-pipermethystine, a minor component in the aerial parts of kava, has been achieved by featuring, as a key step, the environmentally friendly and direct synthesis of 2,3-epoxyamides from allyl amines. By using the chiron approach, first a carbohydrate-derived dehydropiperidine was prepared and subjected to a stereoselective tandem C-H/CC oxidation reaction. In this attempt, the required α,α-trans-epoxy-2-piperidone skeleton of the kava metabolite precursor was not achieved, although the tandem oxidation was highly stereoselective. However, starting from non-carbohydrate 3-hydroxy-4,5-dehydropiperidine, and using the same tandem oxidation, the target intermediate was obtained in high yield and complete unprecedented anti-stereoselectivity. Since the proposed mechanistic course of this tandem oxidation implies the transient formation of an α,β-unsaturated amide followed by the subsequent epoxidation reaction, this second approach supports the previously established biotransformation proposal of (-)-pipermethystine to (-)-3α,4α-epoxy-5β-pipermethystine.
Rapid additions of bulky tert-butyldimethylsilyl cyanide to hindered ketones promoted by heterogeneous tin ion-exchanged montmorillonite catalyst
Wang, Jiacheng,Masui, Yoichi,Hattori, Taiki,Onaka, Makoto
experimental part, p. 1978 - 1981 (2012/05/05)
Tin ion-exchanged montmorillonite (Sn-Mont) was found to be a powerful heterogeneous catalyst for the cyanosilylation of various ketones including congested ones with a bulky cyanide source, tert-butyldimethylsilyl cyanide (TBDMSCN), giving the corresponding cyanohydrin tert-butyldimethylsilyl ethers in good (85%) to excellent (>98%) yields at room temperature. Compared to the previously reported catalysts, Sn-Mont is easy to prepare, environmentally benign, nontoxic, noncorrosive, and recyclable.
Lithium chloride: An active and simple catalyst for cyanosilylation of aldehydes and ketones
Kurono, Nobuhito,Yamaguchi, Masayo,Suzuki, Ken,Ohkuma, Takeshi
, p. 6530 - 6532 (2007/10/03)
LiCl acts as a highly effective catalyst for cyanosilylation of various aldehydes and ketones to the corresponding silylated cyanohydrins. The reaction proceeds smoothly with a substrate/catalyst molar ratio of 100-100 000 at 20-25 °C under solvent-free conditions. α,β-Unsaturated aldehydes are completely converted to the 1,2-adducts. The cyanation products can be isolated by direct distillation of the reaction mixture.
Reduction of α-Trialkylsiloxy Nitriles with Diisobutylaluminium Hydride (DIBAH): A Facile Preparation of α-Trialkylsiloxy Aldehydes and their Derivatives
Hayashi, Masahiko,Yoshiga, Tomoko,Nakatani, Kanako,Ono, Kazuyuki,Oguni, Nobuki
, p. 2821 - 2830 (2007/10/02)
The stepwise synthesis of α-trimethylsiloxy aldehydes and α-hydroxy aldehydes could be achieved via the reduction of α-trimethylsiloxy nitriles with diisobutylaluminium hydride (DIBAH) starting from a variety of ketones.The facile synthesis of optically active α-tert-butyldimethylsiloxy aldehydes was attained by combination of asymmetric silylcyanation of aldehydes and DIBAH reduction of optically active α-siloxy nitriles.Furthermore, in the reduction of some α-tert-butyldimethylsiloxy-β,γ-unsaturated nitriles, migration of the double bond took place to form more stable α-siloxy-α,β-unsaturated aldehydes under some reaction conditions.
