78342-45-7

Basic information

• Product Name: (2S,5R)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-(3-phenyl-2-propyn-1-yl)pyrazine
• Synonyms: (2S,5R)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-(3-phenyl-2-propyn-1-yl)pyrazine
• CAS NO: 78342-45-7
• Molecular Weight: 298.385
• Mol File: 78342-45-7.mol
• Article Data: 4

Chemical Properties

• CAS DataBase Reference: (2S,5R)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-(3-phenyl-2-propyn-1-yl)pyrazine(CAS DataBase Reference)
• NIST Chemistry Reference: (2S,5R)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-(3-phenyl-2-propyn-1-yl)pyrazine(78342-45-7)
• EPA Substance Registry System: (2S,5R)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-(3-phenyl-2-propyn-1-yl)pyrazine(78342-45-7)

Safety Data

• Hazardous Substances Data: 78342-45-7(Hazardous Substances Data)

Upstream product

• 60654-81-1 ethyl L-valylglycinate 
• 78342-42-4 (S)-2-isopropyl-3,6-dimethoxy-2,5-dihydropyrazine 
• 1794-48-5 1-bromo-3-phenylprop-2-yne 
• 24601-74-9 (S)-4-isopropyloxazolidine-2,5-dione 
• 53932-18-6 methyl 2-(2-amino-3-methylbutanamido)acetate 
• 16944-60-8 (2S)-isopropylpiperazine-3,6-dione 
• 4289-97-8 N-formyl-L-valine 
• 72-18-4 L-valine 
• 591-50-4 iodobenzene 
• 78342-46-8 (2R,5S)-5-isopropyl-3,6-dimethoxy-2-propargyl-2,5-dihydropyrazine 

Downstream Products

• 4070-48-8 L-Valine methyl ester 
• 78342-49-1 (S)-2-Amino-5-phenyl-pent-4-ynoic acid methyl ester 
• 78342-49-1 (R)-2-Amino-5-phenyl-pent-4-ynoic acid methyl ester 

Relevant articles and documents

Asymmetric synthesis of α-allenylglycines

The coupling of the homocuprate of the bislactim ether of cyclo-(-L-Val-Gly-) (9) with primary propargyl halides produces the allenyl-substituted bislactim ethers 11 in a highly diastereoselective manner, whereas the alkylation of the lith-iated bislactim ether of cyclo-(-L-Val-Gly-) yields the proparg-yl-substituted bislactim ethers 12. Subsequent hydrolysis affords, after protection of the amino group, the methyl α- allenylglycinates 15, the α-allenylglycines 16, and the methyl α-propargylglycinates 17.

ENANTIOSELECTIVE SYNTHESIS OF NON-PROTEINOGENIC AMINO ACIDS VIA METALLATED BIS-LACTIM ETHERS OF 2,5-DIKETOPIPERAZINES

Bis-lactim ethers 1 of 2,5-diketopiperazines contain a chiral inducing center, an acidic CH-bond and two sites susceptible to hydrolysis.They react with BuLi to give Li compounds of type 4, 15, 29 or 32, which possess a prochiral C atom.They readily add electrophiles (such as alkylating agents or carbonyl compounds) with unusually high diastereoface differentiation.In many cases the d.e-value (d.e. = diastereomeric excess = asymmetric induction) of the adduct exceeds 95percent.On hydrolysis the adducts are cleaved liberating the chiral auxiliary (used to build up the bis-lactim ether 1) and the target molecules, the optically active amino acid methyl esters of type 8, 19, 25 or 36.The two amino acid esters are separable either by fractional distillation or (eventually after further hydrolysis to amino acids) by chromatography.Transition state models are discussed that could explain the exceptionally high asymmetric induction and the predictability of the induced configuration.