162872-57-3Relevant academic research and scientific papers
Synthesis of (+)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid, a diastereoselective approach
Bu??yszko, Ilona,Chrzanowska, Maria,Grajewska, Agnieszka,Rozwadowska, Maria D.
, p. 383 - 388 (2015)
The diastereoselective synthesis of (+)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (90% ee) was accomplished by employing a combination of two synthetic methods, that is, the Petasis synthesis of amino acids and the Pomeranz-Fritsch-Bobbitt synthesis of tetrahydroisoquinoline derivatives. The stereochemical outcome of the synthesis was controlled by chiral aminoacetaldehyde acetals, which were used as the amine component of the Petasis step to yield the Pomeranz-Fritsch-Bobbitt substrate for the tetrahydroisoquinoline ring formation in one simple operation.
Chiral azole derivatives. 2. Synthesis of enantiomerically pure 1-alkylimidazoles
Corelli,Summa,Brogi,Monteagudo,Botta
, p. 2008 - 2015 (2007/10/02)
4,5-Dicyanoimidazole has been reacted with racemic and enantiopure alcohols 7 (entries 1-7) under Mitsunobu conditions to give 1-alkyl-4,5-dicyanoimidazole derivatives 8, which in turn have been transformed by hydrolysis and decarboxylation into 1-alkylimidazoles 10 in good overall yield and high enantiomeric excess. In contrast, when applied to benzyl and benzhydryl alcohols (entries 8-15), this sequence afforded the final compounds in good overall yield, but as racemic mixtures. The 1-(1-phenylalkyl)imidazole derivative (S)-(+)-24 was, however, prepared in enantiopure form starting from the corresponding (S)-(-)-α-methylbenzylamine (21) using the Marckwald procedure, which entailed the alkylation of 21 with bromoacetaldehyde dimethyl acetal, followed by the construction of the imidazole ring through reaction with potassium thiocyanate and final Ra-Ni desulfuration. Following the same procedure, (S)-(+)-10c was also synthesized, proving the stereochemical outcome of the Mitsunobu reaction.
