83553-80-4Relevant academic research and scientific papers
Chemistry of opium alkaloids, 45. Improvements in the total synthesis of morphine
Meuzelaar, Gerrit J.,Van Vliet, Michiel C. A.,Maat, Leendert,Sheldon, Roger A.
, p. 2315 - 2321 (2007/10/03)
The chiral 1,2,3,4-tetrahydroisoquinoline intermediates in the Price and Beyerman routes to morphine, (+)-(R)-1-(3-hydroxy-4-methoxybenzyl)-6-methoxy- 1,2,3,4-tetrahydroisoquinoline (6) and (+)-(R)-1-(3,5-dibenzyloxy-4- methoxybenzyl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline (5), were prepared in high ee by ruthenium-catalyzed asymmetric transfer hydrogenation of the corresponding imine precursors (Noyori method). The yield of the key raw material in the Beyerman route, 3,5-dibenzyloxy-4-methoxyphenylacetric acid (1), starting from gallic acid methyl ester (7) was improved by a factor of 5 over previously described syntheses. Key steps in the new procedure are the selective formation of methyl 3,5-dihydroxy-4-methoxybenzoate (9) via the 3,5-diacetate and an improved benzylation of the hydroxyl groups in 9.
Novel chemoselective de-esterification of esters of polyacetoxy aromatic acids by lipases
Parmar, Virinder S.,Kumar, Ajay,Bicht, Kirpal S.,Mukherjee, Shubhasish,Prasad, Ashok K.,Sharma, Sunil K.,Wengel, Jesper,Olsen, Carl E.
, p. 2163 - 2176 (2007/10/03)
Candida cylindracea lipase (CCL) and porcine pancreatic lipase (PPL) have been used for deacetylation of peracetates of methyl and ethyl esters of six different polyphenolic acids in organic solvents. Exclusive de-esterification of the ester groups derived from the phenolic hydroxy and aliphatic acid over the ester group of the aromatic acid and aliphatic alcohol has been achieved affording the corresponding esters of phenolic acids in as high yields as 90-97%. The results have been corroborated with the mechanism of lipase action.
VOM RADIOAKTIVEN CONIFERIN ZUM MARKIERTEN TURGORIN
Schildknecht, Hermann,Milde, Reiner
, p. 23 - 32 (2007/10/02)
The first Periodic Leaf Movement Factor ("PLMF 1"), 4-O-(β-D-glucopyranosyl 6-sulfate)gallic acid (1), which is chemonastically active on Mimosa pudica L., and its (14)C-carboxyl-labelled analog were synthesized by Koenigs-Knorr reaction of a D-glucose derivative with a suitably blocked gallic acid to give 4-O-β-D-glucopyranosylgallic acid after deblocking.Regioselective sulfatation with sulfur trioxide-pyridine afforded 1.The (14)C-labelled analog was prepared via regioselective glucosylation of methyl galloate with 2,3,4,6-tetra-D-acetyl-α-D-glucopyranosyl bromide and subsequent sulfatation of the deblocked glucoside.
