115706-57-5Relevant articles and documents
General approach to anthrapyran antibiotics exemplified by the synthesis of rac-γ-indomycinone
Krohn, Karsten,Tran-Thien, Hoan Trang,Ahmed, Ishtiaq
, p. 2223 - 2225 (2011)
A new general route to the anthrapyran antibiotics is presented, which allows the attachment of various branched side chains. A key step is the Baker-Venkataraman rearrangement of the propionate 9 to the diketone 10. Acid-catalyzed cyclization gives the ethyl-branched anthrapyranone 11, serving as the starting material for further side-chain elongation. For example, the ethyl-substituted anthrapyranones 12a,b,c, the corresponding bromides 13b,c, the phosphonium salts 14b,c, the olefins 22a,c, and the epoxides 23a,c are prepared by starting from 11. A first example demonstrating the potential of this route is the synthesis of the naturally occurring γ-indomycinone (24b), prepared bycuprate-mediated opening of the epoxide 23a. A general route to the anthrapyran antibiotics is presented, which allows the attachment of various branched side chains. In a first example, an ethyl-branched anthrapyranone, prepared in a Baker-Venkataraman rearrangement, was used to obtain a 1-methylvinyl-substituted anthrapyranone that was transformed into rac-indomycinone via an intermediate epoxide in a cuprate-mediated epoxide opening. Copyright
Total synthesis of aklanonic acid and derivatives by Baker-Venkataraman rearrangement
Krohn, Karsten,Roemer, Ernst,Top, Michael
, p. 271 - 277 (2007/10/03)
Aklanonic acid (1) and the derivatives 2 and 15a-f were prepared by Baker-Venkataraman rearrangement of the corresponding ortho-acetyl anthraquinone esters 13a-e and 14 using lithium hydride in THF. VCH Verlagsgesellschaft mbH, 1996.
