1433498-28-2Relevant articles and documents
Synthesis of the AB-ring pyranolactone substructure of granaticin A
Bartholomaeus, Ruben,Bachmann, Janina,Mang, Christian,Haustedt, Lars Ole,Harms, Klaus,Koert, Ulrich
, p. 180 - 190 (2013/02/23)
A synthesis of the AB-ring substructure of granaticin A was developed. The pyranolactone moiety was stereoselectively accessed by Sharpless asymmetric dihydroxylation and subsequent oxa-Pictet-Spengler cyclization. The use of BF3·OEt2 resulted in the formation of the cis pyranolactone, whereas the combination of BF3·OEt2 with trifluoroacetic acid led to the trans isomer. The resulting hydroquinones were cleaved selectively by ozonolysis to dicarboxylic acids. An aryl Grignard reagent could be regioselectively added to unsymmetrical anhydrides. As an alternative strategy for the construction of the B-ring, a benzyne-furan cycloaddition could be established. Synthesis of the AB-ring substructure of granaticin A was accomplished. The pyranolactone moiety was stereoselectively accessed by Sharpless asymmetric dihydroxylation and oxa-Pictet-Spengler cyclization. Ozonolysis of a hydroquinone led to pyranolactone anhydrides. Regioselective addition of a Grignard reagent to an unsymmetrical anhydride was observed. An alternative strategy was also investigated. Copyright
