52703-75-0

Upstream product

• 473253-68-8 benzo[1,3]dioxol-5-yl-(2-hydroxymethyl-4,5-dimethoxyphenyl)methanol 
• 120-57-0 piperonal 
• 54370-00-2 2-bromo-4,5-dimethoxybenzyl alcohol 
• 5392-10-9 2-bromo-4,5-dimethoxybenzaldehyde 

Downstream Products

• 95436-24-1 dimethyl 1-(benzo[d][1,3]dioxol-5-yl)-6,7-dimethoxynaphthalene-2,3-dicarboxylate 
• 42298-61-3 6,7-dimethoxy-1-(benzo[1,3]dioxol-5-yl)naphthalene-2,3-dicarboxylic acid 2-methyl ester 
• 92753-33-8 5,6-Dimethoxy-3-(1,3-benzodioxol-5-yl)isobenzofuran-1(3H)-one 
• 17951-19-8 justicidin B 

Relevant academic research and scientific papers

A new benzannulation reaction and its application in the multiple parallel synthesis of arylnaphthalene lignans

A new aromatic annulation reaction based on sequential Horner-Emmons and Claisen condensation reactions is described. The method is high yielding and provides a rapid entry to arylnaphthalenes. The lignan natural products justicidin B 1, retrojusticidin B 2, taiwanin C 3, justicidin E 4, chinensin 5 and retrochinensin 6 have all been synthesised in good overall yield using this protocol, demonstrating its potential in multiple parallel synthesis. The selective oxidation of diols 34-36 to the corresponding retrolactones with barium manganate(VI) is also noteworthy.

Total syntheses of justicidin B and retrojusticidin B using a tandem Horner-Emmons-Claisen condensation sequence

Short syntheses of justicidin B 1 and retrojusticidin B 4 are reported. The key feature is a new annulation reaction, involving a base induced union of ketoaldehyde 2 and phosphonate 3, that is used to construct the highly substituted naphthalene core.