213970-74-2

Upstream product

• 67-56-1 methanol 
• 201230-82-2 carbon monoxide 
• 213970-73-1 (E)-3-[3-(4-Benzyloxy-3-methoxy-phenylethynyl)-4-hydroxy-5-methoxy-phenyl]-acrylic acid ethyl ester 
• 1530-45-6 (carbethoxymethyl)triphenylphosphonium bromide 
• 473240-36-7 2-(4-benzyloxy-3-methoxyphenyl)-3-methoxycarbonyl-7-methoxybenzofuran-5-carboxaldehyde 
• 144735-54-6 1-ethynyl-4-(benzyloxy)-3-methoxybenzene 

Downstream Products

• 242474-37-9 5-(2-Ethoxycarbonyl-ethyl)-2-(4-hydroxy-3-methoxy-phenyl)-7-methoxy-benzofuran-3-carboxylic acid methyl ester 
• 473240-39-0 (E)-2-(4-benzyloxy-3-methoxyphenyl)-3-hydroxymethyl-5-(3-hydroxyprop-1-en-1-yl)-7-methoxybenzofuran 
• 135040-83-4 5-(3-hydroxypropyl)-7-methoxy-2-(3'-methoxy-4'-hydroxyphenyl)-3-benzo[b]furan-carbaldehyde 
• 70610-22-9 2-(3-methoxy-4-hydroxyphenyl)-3-methoxycarbonyl-5-(3-hydroxypropyl)-7-methoxybenzo[b]furan 

Relevant academic research and scientific papers

A novel strategy for the synthesis of benzofuran skeleton neolignans: Application to ailanthoidol, XH-14, and obovaten

A convenient and general approach to the synthesis of the benzofuran skeleton compounds ailanthoidol, XH-14, and obovaten was developed. Starting from vanillin, a series of reactions afforded 7 in 71% yield. Treatment of 7 with n-BuLi followed by addition of substituted benzaldehydes resulted in the formation of carbinols 11 and 31. The substituted benzophenones obtained from oxidation of 11 and 31 were treated with trimethylsilyldiazomethane lithium salt to give diphenylacetylenes 15 and 33, respectively. 15 and 33 were then cyclized in the presence of either mercury acetate in acetic acid or bromine in chloroform to give 3-chloromercurio- or 3-bromobenzofuran, respectively. The 3-chloromercurio intermediates could be reduced to proton or derivatized to ester or bromide, leading to the synthesis of ailanthoidol, XH-14, and obovaten, respectively. In addition, necleophilic substitution was used to introduce a formyl or methyl group into the 3-bromobenzofuran derivatives, providing an alternative pathway to XH-14 and obovaten. The final elongation and deprotection reaction furnished the desired ailanthoidol, XH-14, and obovaten in yields of 30, 15, and 11%, respectively.

Synthesis of 2-substituted 3-acylbenzo[b]furans via the palladium catalysed carbonylative cyclisation of ortho-hydroxytolans

A palladium-catalysed cyclisation with concomitant carbonylation via insertion of carbon monoxide was used to prepare several potential adenosine antagonists possessing a benzo[b]furan skeleton with a formyl group in the 3-position.

Synthesis of natural products possessing a benzo[b]furan skeleton

A related synthetic strategy has been used to prepare two natural products XH-14 and ailanthoidol) which possess a benzo[b]furan skeleton. The synthesis of XH-14 involved the use of a palladium-catalyzed cyclization with concomitant carbonylation via insertion of carbon monoxide to introduce regioselectively a formyl group in the 3-position.