65025-65-2Relevant academic research and scientific papers
Concise Synthesis of Anti-HIV-1 Active (+)-Inophyllum B and (+)-Calanolide A by Application of (-)-Quinine-Catalyzed Intramolecular Oxo-Michael Addition
Sekino, Etsuko,Kumamoto, Takuya,Tanaka, Tomohiro,Ikeda, Tomoko,Ishikawa, Tsutomu
, p. 2760 - 2767 (2007/10/03)
(-)-Quinine-catalyzed intramolecular oxo-Michael addition (IMA) of 7-hydroxy-5-methoxy-8-tigloylcoumarins was developed for the enantioselective construction of 2,3-dimethyl-4-chromanone systems in the context of the asymmetric synthesis of anti-HIV-1 act
Synthesis of the Calophyllum coumarins. Part 2
Palmer, Christopher,Josephs, Jonathan
, p. 3135 - 3152 (2007/10/03)
Synthetic routes leading to the synthesis of the natural 4-phenyl, 4-propyl and 4-methyl coumarins isolated from Calophyllum sp. are presented. 4-Aryl or -alkyl, 8- and 6-acyl 5,7-dihydroxy coumarins were chromenylated and then methylated at the 5 or 7 positions.A 4-step hydrobromination-bromination-double dehydrobromination sequence converted the 2-methylbutanoyl side chain into the (E)-2-methylbut-2-enoyl (tigloyl) group to give calophyllolide, oblongulide, their natural 4-propyl analogue and the corresponding regioisomers.Demethylation and cyclisation of the tigloyl group gave inophyllums C and E, tomentolides A and B, and calanolide D.Sodium boranuide reduction of the 2,3-dimethylchromanone ring afforded inophyllums A, B, D and P, soulattrolide, calanolides A-C, costatolide, and cordatolides A and B.The structures of calanolides C and D, oblongulide and apetatolide have been reassigned.The previously unknown stereochemistry about the 2,3-dimethylchromanone ring of tomentolides A and B has been established as trans.
Synthesis of the calophyllum coumarins
Palmer, Christopher J.,Josephs, Jonathan L.
, p. 5363 - 5366 (2007/10/02)
Synthetic routes leading to the synthesis of the natural 4-alkyl and 4- phenyl coumarins isolated from Calophyllum sp. are reported. The reported structures of calanolides C and D and oblongutide are incorrect and have been corrected by unambiguous synthesis.
