58434-48-3Relevant academic research and scientific papers
Efficient total synthesis of AI-77-B, a gastroprotective substance from Bacillus pumilus AI-77
Hamada,Hara,Kawai,Kohno,Shioiri
, p. 8635 - 8652 (2007/10/02)
First total synthesis of AI-77-B (1), a gastroprotective substance from Bacillus pumilus AI-77, was achieved in a stereoselective and convergent manner. In this synthesis, the dihydroisocoumarin part 2 was constructed in one step through 1,2-addition of the benzylic anion 17b to Boc-L-leucinal 7b. The hydroxy amino acid 4 was elaborated from (R)-glutamic acid in a highly stereoselective manner. Condensation of 2·HCl and 4, intramolecular Pinner reaction, followed by mild hydrolysis afforded AI-77-B (1).
REGIOSELECTIVE METALLATIONS OF (METHOXYMETHOXY)ARENES
Ronald, Robert C.,Winkle, Mark R.
, p. 2031 - 2042 (2007/10/02)
The methoxymethoxy substituent when attached to an aromatic ring functions as a moderately strong ortho-directing group in hydrogen-metal exchenge reactions.In many cases the propensity of the methoxymethoxylated arene toward ring metallations is greatly enhanced with concomitant suppression of undesirable side reactions such as nucleophilic attack and addition of metallating species.Unlike many other ortho-directing groups, the regio-direction of the methoxymethoxy substituent when in conjunction with other weaker directing groups is dependent upon the metallating medium.Thus, by changing the electron donating capacity of the metallating medium it is possible to selectively direct metallation to either of the positions ortho to the methoxymethoxy substituent.
