Pyrano acridin-7 -one

Chemical Name 7H-Pyrano[2,3-c]acridin-7-one, 3,12-dihydro-6-methoxy-3,3,12-trimethyl-... 

Bhavsar and his co-workers reported the formation of pyrano[2,3-a] acridin-2-ones, such as 199, from 8-aroyl-7-hydroxy-benzopyran-2-ones,... 

The coupling of 2,3-dihydroxy-10-methylacridin-9(10//)-one 276 with 3-chloro-3-methylbut-l-yne afforded a pyrano[3,2-a]acridine 277 (Scheme 48) (83MI1). 

Since the discovery of the broad experimental antitumor spectrum of acronycine in 1966, more than one hundred compounds derived from the 3,12-dihydro-7//-pyrano[2,3c]acridin-7-one basic skeleton have been synthesized or isolated from natural sources. Unfortunately, many of these compounds have not been studied from a biological point of view. Only a few have been tested in vitro for cytotoxic activity. Even fewer have been studied in vivo for antitumor properties. In addition, the experimental conditions and the cell lines used for the tests greatly vary from one compound to another. It nevertheless seems possible to draw some limited... 

The substituent at C-6 on the C-ring has a dramatic influence on the antitumor activity in the 3,12-dihydro-7//-pyrano[2,3c]acridin-7-one series. 

Using Upjohn condition (OsOi-NMO). The utility of the Upjohn protocol for the dihydroxylation was recently demonstrated in the synthesis of bicyclic analogues of pentopyranoses, (-)-anisomycin, trisubstituted y-butyrolactone, 6-bromo-4-(l,2-dihydroxyethyl)-7-hydroxycoumarine (Bhc-diol) as a photoremovable protecting group, 3,4-dihydroxy-2-(3-methylbut-2-enyl)-3,4-dihydronaphthalen-l(2//)-one, benzo-[c]pyrano[3,2-/z]acridin-7-ones, both enantiomers of conduri-tol C tetraacetate and of mei o-conduritol-D-tetraacetate. ... 

Trihydroxy-4-methoxy-10-methyl-2,8-Ws(3-methylbut-2-enyl) acridin-9(10//)-one, l,5-dihydToxy-2,3-dimetboxy-10-metbyl-9-acridone, 2,3-Dibydro-4,9-dihydToxy-2-(2-bydroxypropan-2-yl)-l 1-metboxy-10-metbylfuro[3,2-b]acridin-5(10//)-one, 3,4-Dihydro-3,5,8-tribydroxy-6-metboxy-2,2,7-trimetbyl-2/f-pyrano[2,3-a]acridin-12(7//)-one, l-metbyl-2-nonylquinolin-4(l//)-one, 2-(pent-l-enyl)quinoline, 2-nonylquinolin-4(l/7)-one, 2-n-pentylquinoline, 2- -propylquinoline,... 

It should be noted that the intermediates in the various syntheses of glycocitrine-II by Anand et cd. also furnished an interesting access to the pyrano[2,3-c]acridin-7-one series. For instance, demethoxylation of intermediate 312 with sodium ethanethiolate in dimethylformamide gave 306, which could be cyclized with 2,3 dichlorO 5,6-dicyano-l,4-benzoquinone to 12-demethylnorara-onydne (313). Methylation of this latter product afforded acronycine (2) (329). 

The synthesis of natural pyranoacridone alkaloids and analogues has received more attention than that of their flirano counterparts, due to the interesting antitumor properties exhibited by acronycine and some of its derivatives. Two main strategies have been developed for the synthesis of pyrano[2,3-c]acridin-7-one and pyrano[3,2-A]acridin-7-one alkaloids. 

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