81136-86-9

Basic information

• Product Name: Pyrazine, 2,5-dihydro-3,6-dimethoxy-2-methyl-5-(1-methylethyl)-
• CAS NO: 81136-86-9
• Molecular Formula: C10H18N2O2
• Mol File: 81136-86-9.mol
• Article Data: 2

Chemical Properties

• CAS DataBase Reference: Pyrazine, 2,5-dihydro-3,6-dimethoxy-2-methyl-5-(1-methylethyl)-(CAS DataBase Reference)
• NIST Chemistry Reference: Pyrazine, 2,5-dihydro-3,6-dimethoxy-2-methyl-5-(1-methylethyl)-(81136-86-9)
• EPA Substance Registry System: Pyrazine, 2,5-dihydro-3,6-dimethoxy-2-methyl-5-(1-methylethyl)-(81136-86-9)

Safety Data

• Hazardous Substances Data: 81136-86-9(Hazardous Substances Data)

Upstream product

• 72-18-4 L-valine 
• 24601-74-9 (S)-4-isopropyloxazolidine-2,5-dione 
• 420-37-1 trimethoxonium tetrafluoroborate 
• 15136-26-2 cyclo(L-Val-D,L-Ala) 
• 28140-49-0 L-Val-D,L-Ala-OCH₃ 

Downstream Products

• 81136-89-2 (2R,5S)-5-Isopropyl-3,6-dimethoxy-2-methyl-2-((E)-3-phenyl-allyl)-2,5-dihydro-pyrazine 
• 81136-87-0 (2S,5R)-2,5-dihydro-2-isopropyl-3,6-dimethoxy-5-benzyl-5-methylpyrazine 
• 81136-88-1 (2R,5S)-2-(3,4-Dimethoxy-benzyl)-5-isopropyl-3,6-dimethoxy-2-methyl-2,5-dihydro-pyrazine 

Relevant articles and documents

Stereoselective Protonation of Carbanions, 2. - Diastereoselective Protonation of Schoellkopf's Bislactim Ether Anions

The anions of the bis-lactim ethers 5-7 serve as model for a systematic investigation of diastereoselective protonation.From 5Li, 6Li, and 7Li in THF at -78 deg C 30 proton sources (-OH, -NH, -SH, -CH) of different acidity and bulkiness produce the following cis/trans ratios: 5 8:92 --> 37:63; 6 15:85 --> 48:52; 7 25:75 --> 59:41 (equilibria ca. 50:50).Substitution of R1 = iPr in 5 by Me (--> 6) decreases the stereoselectivity slightly, but substitution of OMe in 6 by OEt (7) much stronger (Table 1).Most of the added Lewis acids show weak or even leveling effects, whereas with 5K a dramatic change is observed with cis/trans-5 = 27:73 --> 89:11 (Table 2).By variation of solvent and several additives only minor effects on the cis/trans ratio are observed (Table 3).Backed by 13C-NMR spectra of the ion pairs and literature data protonation of 5Li-7Li is supposed to occur on a dimer, which will mainly react to give trans-5-7.The prevailing formation of cis-5 from 5K is explained by the reaction of the monomeric ion aggregat. - Key Words: Diastereoselectivity / Protonation / Pyrazines, dialkoxydihydro-