401792-87-8

Upstream product

• 4434-13-3 2-carboxy-5-methylpyridine 
• 17228-64-7 6-chloro-2-methoxypyridine 
• 67-56-1 methanol 
• 201230-82-2 carbon monoxide 
• 95652-81-6 6-chloro-2-methoxy-3-pyridinecarboxaldehyde 
• 2402-78-0 2,6-dichloropyridine 
• 401792-82-3 methyl 6-methoxy-5-methyl-2-pyridinecarboxylate 
• 401792-80-1 methyl 6-hydroxy-5-methyl-2-pyridinecarboxylate 
• 401792-77-6 methyl 5-methyl-2-pyridinecarboxylate N-oxide 
• 29681-38-7 methyl 5-methylpyridine-2-carboxylate 
• 589-93-5 2,5-dimethylpyridine 
• 401792-84-5 methyl 5-(bromomethyl)-6-methoxy-2-pyridinecarboxylate 

Downstream Products

• 1585241-69-5 (S)-5-benzhydryl 1-tert-butyl 3-((S)-1-(2-methoxy-6-(methoxycarbonyl)pyridin-3-yl)-2-nitroethyl)-2-oxopentanedioate 
• 1585241-70-8 C₃₂H₃₆N₂O₇ 
• 1585241-82-2 (2R,3S,4S)-1-benzyl 2-tert-butyl 3-(2-methoxy-2-oxoethyl)-4-(2-methoxy-6-(methoxycarbonyl)pyridin-3-yl)pyrrolidine-1,2-dicarboxylate 
• 1585241-72-0 C₂₄H₂₆N₂O₉ 
• 1585241-73-1 (2S,3S,4S)-1-((benzyloxy)carbonyl)-3-(2-methoxy-2-oxoethyl)-4-(2-methoxy-6-(methoxycarbonyl)pyridin-3-yl)pyrrolidine-2-carboxylic acid 
• 86630-09-3 Acromelic acid A 
• 1585241-94-6 C₂₆H₃₀N₂O₁₀ 
• 478946-91-7 5-((S)-2-Benzyloxycarbonylamino-2-carboxy-ethyl)-6-methoxy-pyridine-2-carboxylic acid 
• 401792-93-6 (+)-methyl N-(benzyloxycarbonyl)-3-[2-(methoxycarbonyl)-6-methoxy-5-pyridinyl]-L-alaninate 

Relevant academic research and scientific papers

Practical total syntheses of acromelic acids A and B

Practical total syntheses of acromelic acids A (1) and B (2), which were scarce natural products isolated from toxic mushroom by Shirahama and Matsumoto, were accomplished in 13 (36% total yield) and 17 steps (6.9% total yield), respectively, from 2,6-dichloropyridine (8). Beginning with regioselective transformation of symmetric 8 by either ortho-lithiation or bromination, nitroalkenes 15 and 16 were provided. Stereoselective construction of the vicinal stereocenters at the C-3, 4 positions of 1 and 2 was performed by a Ni-catalyzed asymmetric conjugate addition of α-ketoesters to the nitroalkenes. Construction of the pyrrolidine ring was accomplished in a single operation via a sequence consisting of reduction of the nitro group, intramolecular condensation with the ketone, and reduction of the resulting ketimine.

Practical total syntheses of acromelic acids A and B

Practical total syntheses of acromelic acids A (1) and B (2), which have potent neuro-excitatory activity, were accomplished in 13 (36% total yield) and 17 steps (6.9% total yield), respectively, from 2,6-dichloropyridine (8). Regioselective transformation of symmetric 8 provided nitroalkenes 15 and 16. The pyrrolidine ring was efficiently constructed by Ni-catalyzed asymmetric conjugate addition followed by intramolecular reductive amination.

Nonproteinogenic amino acids: An efficient asymmetric synthesis of (S)-(-)-acromelobic acid and (S)-(-)-acromelobinic acid

An efficient synthesis of (S)-(-)-acromelobic acid (1) and (S)-(-)-acromelobinic acid (2) is described via asymmetric hydrogenation protocol. Asymmetric hydrogenation of dehydroamino acid derivative 23 using (R,R)-[Rh(DIPAMP)(COD)]BF4 catalyst followed by removal of the protective groups afforded (S)-(-)-acromelobic acid (1) in >98% ee. The key intermediate 23 was prepared from citrazinic acid (8). The dehydroamino acid derivative 33 required for the synthesis of (S)-(-)-2 was prepared from 2,5-lutidine (27), which upon hydrogenation using (S,S)-[Rh(Et-DuPHOS)(COD)]BF4 catalyst afforded (S)-(+)-34 in 93% yield and >96% ee. Removal of protective groups in (S)-(+)-34 afforded (S)-(-)-acromelobinic acid (2) in good overall yield.

Asymmetric synthesis of (S)-(-)-acromelobinic acid

A total synthesis of (S)-(-)-acromelobinic acid 2, which was isolated from clitocybe acromelalga, was achieved via an asymmetric hydrogenation protocol. Dehydroamino acid derivative 12 was prepared from 2,5-lutidine 5 and subjected to asymmetric hydrogenation using (S,S)-[Rh(Et-DuPHOS)(COD)]BF4 to give the (S)-(+)-pyridylalanine derivative 13 in 93% yield and >96% e.e. Removal of the protecting groups in (S)-(+)-13 afforded (S)-(-)-acromelobinic acid 2.