Quinacetophenone: A simple precursor to privileged organic motifs

On the Reaction of 2-Alkanoylnaphthohydroquinones with Hydroxylamine: Access to Cytotoxic 2-(Hydroxyamino)-1,4-naphthoquinone and Their 3-(Hydroxyimino)alkyl Analogous

“…Since the synthesis of acetylhydroquinone oxime II from hydroquinone I (R � CH 3 ) and hydroxylamine has been reported with high yield [16] and based on standard procedures to prepare acetophenone oximes [22], the reactivity of acetylhydroquinones III leading to the corresponding oximes IV was first explored. In this context, Scheme 1 shows the synthesis of the required precursor 2-acetylnaphthohydroquinone 2 from 1,4-naphthoquinone 1 and acetaldehyde, according to our previously reported procedure based on the solar photoacylation Friedel-Crafts reaction [12].…”

“…The synthetic advantage of these acylhydroquinones [9][10][11][12][13][14] emerges from the coexistence of the hydroquinone and the ortho-hydroxyacylarene fragments in their structures. Within this group of acetylhydroquinones, the simplest naturally occurring member named quinacetophenone stands out by its property to inhibit the growth of diverse myeloma cells [15] and by its extensive use as a synthetic precursor of organic molecules such as chalcones, flavonoids, chromones, coumarins, quinones, and psoralens, relevant in medicinal chemistry [16].…”

“…The abovementioned replacement approach requires precursors II and IV. Since access to oxime II from I (R � CH 3 ) has been reported [16], we focused our attention on the synthesis of oxime type IV from III.…”

Recent advances in the synthesis of 4H-chromen-4-ones (2012 − 2021)

“…The importance of specific reagents, namely, molecular iodine in the synthesis of 2-aryl-, 2-styryl-and 2-aryl-3-iodo-4H-chromen-4-ones 31 ; quinacetophenone as an easily accessible building block for the synthesis of various 2-and 3-substituted and 2,3-disubstituted 4H-chromen-4-ones; 32 the use of heteropolyacids as catalysts for the synthesis of 2-aryl-4H-chromen-4-ones; 33 2-hydroxyaryl tertiary enaminones for the synthesis of C-3-functionalized chromones via tandem vinyl CdH bond elaboration and chromone annulation reactions; 34 acyclic 2-hydroxyaryl enaminones for the synthesis of 3-acyl-4H-chromen-4-ones; 35 2-hydroxyaryl N,N-dimethylenaminones for the synthesis of 2,3-unsubstituted, 2-and 3-substituted 4H-chromen-4-ones; 36 and 2,3-unsubstituted 4H-chromen-4-ones for diversification of their chromone unit by direct CdH bond activation/functionalization at C-2 and C-3 sites 37 have been disclosed.…”