548-28-7

Upstream product

• 628-13-7 pyridine hydrochloride 
• 548-27-6 calophyllolide 
• 172805-18-4 5-Hydroxy-2,2-dimethyl-6-<(E)-2-methylbut-2-enoyl>-10-phenyl-2H,8H-benzo<1,2-b:3,4-b'>dipyran-8-one 
• 5302-74-9 mammea A/BB cyclo D 
• 31525-67-4 dimethylacetal of 3-methyl-3-hydroxybutyraldehyde 
• 98192-65-5 5,7-Dihydroxy-8-(2-methylbutanoyl)-4-phenyl-2H-chromen-2-one 
• 161633-70-1 5-Methoxy-2,2-dimethyl-6-(2-methylbutanoyl)-10-phenyl-2H,8H-benzo<1,2-b:3,4-b'>dipyran-8-one 
• 172805-13-9 6-(2-Bromo-2-methylbutanoyl)-5-methoxy-2,2-dimethyl-10-phenyl-2H,8H-benzo<1,2-b:3,4-b'>dipyran-8-one 

Downstream Products

• 121968-71-6 (+/-)-3c-(5-methoxy-2r,3t,8,8-tetramethyl-4-oxo-3,4-dihydro-2H,8H-pyrano[2,3-f]chromen-6-yl)-3t-phenyl-acrylic acid methyl ester 
• 477-23-6 (+/-)-3c-(5-hydroxy-2r,3t,8,8-tetramethyl-4-oxo-3,4-dihydro-2H,8H-pyrano[2,3-f]chromen-6-yl)-3t-phenyl-acrylic acid 
• 41135-08-4 (10R,11S,12R)-12-Hydroxy-6,6,10,11-tetramethyl-4-phenyl-11,12-dihydro-6H,10H-dipyrano[2,3-f;2',3'-h]chromen-2-one 
• 41135-08-4 (+/-)-Inophyllum B 

Relevant academic research and scientific papers

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.