89074-04-4

Upstream product

• 89074-02-2 9-(1-hydroxyethyl)-6a,7,10,10a-tetrahydro-5,6,11,12-naphthacenetetraone 
• 89074-03-3 9-(1-hydroxyethyl)-7,10-dihydro-6,11-dihydroxy-5,12-naphthacenedione 

Relevant academic research and scientific papers

A DIELS-ALDER SYNTHETIC APPROACH TO RACEMIC 4-DEMETHOXYDAUNOMYCINONE

(+/-)-4-Demethoxydaunomycinone, 3, was prepared starting from quinizarin diquinone, 4, and 2-(1-hydroxyethyl)-1,3-butadiene, 5.The tautomerised Diels-Alder adduct 8 so obtained was epoxidised to give 9.Cleavage of the oxirane with NaBr/TsOH in 2,2-dimethoxypropane followed by reductive debromination with Bu3SnH gave the diphenol dioxolane 11.This material, after protection of the phenolic groups and liberation of the diol moiety, was oxidised to the 4-demethoxy-7-deoxydaunomicinone dimethyl ether, 15, by (Bu3Sn)2O/Br2.Conversion of 15 to (+/-)-4-demethoxydaunomycinone was performed via a known sequence.