223578-16-3

Upstream product

• 223578-06-1 4,5-dimethoxy-2,3,6-tris(ethoxycarbonyl)pyridine 
• 186581-53-3 diazomethane 
• 223578-09-4 2-<(4'-butyl-3'-methoxy-2'-(methoxymethoxy)phenyl)carbonyl>-4,5-dimethoxy-6-(methoxycarbonyl)pyridine-3-carboxylic acid 
• 223578-07-2 4,5-dimethoxypyridine-2,3,6-tricarboxylic acid 
• 223578-08-3 4,5-dimethoxy-6-(methoxycarbonyl)pyridine-2,3-dicarboxylic acid anhydride 
• 223578-05-0 1-butyl-2-methoxy-3-(methoxymethyl)benzene 

Downstream Products

• 223578-24-3 2-(4'-butyl-3'-methoxy-2'-(methoxymethoxy)phenyl)methyl-4,5-dimethoxy-6-(methoxycarbonyl)pyridine-3-carboxylic acid 
• 223578-23-2 methyl 3-(4'-butyl-3'-methoxy-2'-(methoxymethoxy)phenyl)-6,7-dimethoxy-1-oxo-1,3-dihydrofuro<3,4-b>pyridine-5-carboxylate 

Relevant academic research and scientific papers

Total synthesis of phomazarin

A concise total synthesis of phomazarin (1) is detailed enlisting a heterocyclic azadiene inverse electron demand Diels-Alder reaction (1,2,4- triazine → pyridine) for preparation of the fully substituted and appropriately functionalized pyridine C-ring. Thus, [4 + 2] cycloaddition (85%) of triethyl 1,2,4-triazine3,5,6-tricarboxylate (2) with trimethoxyethylene (3) followed by conversion of the cycloadduct 11 to the cyclic anhydride 13 provided the phomazarin C-ring with the three carboxylates suitably differentiated. Linkage of the A- and C-rings through selective nucleophilic addition of the aryllithium reagent 9 to the least hindered anhydride carbonyl of 13 followed by Friedel-Crafts closure of the B-ring provided the fully functionalized phomazarin skeleton. The successful structural correlation of synthetic 1 with natural material and its derivatives confirmed the latest structural assignment for the natural product.