30390-18-2

Upstream product

• 125074-06-8 2-methyl-1-(2,4,6-trihydroxyphenyl)-1-butanone 
• 5856-79-1 iso-butyl chloroformate 
• 108-73-6 3,5-dihydroxyphenol 
• 7058-70-0 5,7-dihydroxy-6-(2-methylbutanoyl)-8-(3-methylbut-2-enyl)-4-phenyl-2H-chromen-2-one 
• 31525-67-4 dimethylacetal of 3-methyl-3-hydroxybutyraldehyde 
• 98192-58-6 5,7-Dihydroxy-6-(2-methylbutanoyl)-4-phenyl-2H-chromen-2-one 

Downstream Products

• 172805-16-2 6-(2-Bromo-2-methylbutanoyl)-5-methoxy-8,8-dimethyl-4-phenyl-2H,8H-benzo<1,2-b:3,4-b'>dipyran-8-one 
• 172805-21-9 5-Hydroxy-8,8-dimethyl-6-<(E)-2-methylbut-2-enoyl>-4-phenyl-2H,8H-benzo<1,2-b:3,4-b'>dipyran-2-one 
• 22562-09-0 (+/-)-Apetatolide 
• 161633-73-4 5-Methoxy-8,8-dimethyl-6-(2-methylbutanoyl)-4-phenyl-2H,8H-benzo<1,2-b:3,4-b'>dipyran-2-one 

Relevant academic research and scientific papers

4-Alkyl- and 4-phenylcoumarins from Mesua ferrea as promising multidrug resistant antibacterials

Supercritical CO2 selectively extracted a series of 4-alkyl and 4-phenyl 5,7-dihydroxycoumarins from Mesua ferrea blossoms. Chemical modifications of the isolated compounds allowed us to confirm the structures elucidated by spectroscopic means and to prepare new derivatives amenable to SAR studies and potential pharmaceutical development. Biological investigations towards the screening on a number of bacteria strains and Plasmodium falciparum, identified compounds 1-9 as weak antiprotozoal agents and potent antibacterials on resistant Gram-positive strains.

Synthesis of the Calophyllum coumarins. Part 2

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

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.