The present invention provides compounds represented by formula (1A), or pharmaceutically acceptable salts. Compounds represented by formula (1A), or pharmaceutically acceptable salts thereof, wherein A.sup.1 and A.sup.2 are identical or different, and each independently C(O)B, C(O)CR.sup.3AR.sup.3BB, CO.sub.2B, C(S)OB, CONR.sup.3CB, C(S)NR.sup.3CB, a hydrogen atom, or the like, wherein A.sup.1 and A.sup.2 are not both hydrogen atoms, wherein B is an optionally substituted 3- to 12-membered monocyclic or polycyclic heterocyclic group, an optionally substituted 3- to 12-membered cyclic amino group, or a group represented by the following formula (B), wherein the 3- to 12-membered monocyclic or polycyclic heterocyclic group and the 3- to 12-membered cyclic amino group have at least one or more secondary nitrogen atoms in the ring; R.sup.1 is a hydrogen atom or the like; R.sup.2A, R.sup.2B, R.sup.2C, and R.sup.2D are identical or different, and each independently a hydrogen atom or the like; and R.sup.8 is alkyl.

##STR00001##

wherein * denotes a bonding position.

The present invention relates to a novel naphtho class of compounds as Stat3 pathway inhibitors and as cancer stem cell inhibitors; to methods of using such compounds to treat cancer; to methods of using such compounds to treat disorders in a mammal related to aberrent Stat3 pathway activity; to pharmaceutical compositions containing such compounds.

The present invention relates to a novel naphtho class of compounds as Stat3 pathway inhibitors and as cancer stem cell inhibitors; to methods of using such compounds to treat cancer; to methods of using such compounds to treat disorders in a mammal related to aberrent Stat3 pathway activity; to pharmaceutical compositions containing such compounds.

A solid form of ()-Ambrox formed by a bioconversion process.

A solid form of ()-Ambrox formed by a bioconversion process.

The problem of the present invention is to provide a useful prodrug compound of a naphthofuran compound. The present invention relates to a compound represented by the formula (IA):

##STR00001##

[wherein each symbol is as described in the DESCRIPTION] or a pharmaceutically acceptable salt thereof.

The problem of the present invention is to provide a useful prodrug compound of a naphthofuran compound. The present invention relates to a compound represented by the formula (IA):

##STR00001##

[wherein each symbol is as described in the DESCRIPTION] or a pharmaceutically acceptable salt thereof.

Compounds of the formulae (I) or (II) ##STR00001##
wherein X is ##STR00002## A is O, S, NR.sub.5 or CR.sub.16R.sub.17; R.sub.1 is for example hydrogen or C.sub.1-C.sub.20alkyl R.sub.2 is for example hydrogen, C.sub.1-C.sub.20alkyl or C.sub.6-C.sub.20aryl R.sub.5 for example is C.sub.1-C.sub.20alkyl; R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 for example independently of each other are hydrogen. C.sub.1-C.sub.20alkyl, halogen, CN or NO.sub.2; Ar.sub.1 is for example unsubstituted or substituted C.sub.6-C.sub.20aryl, C.sub.3-C.sub.20heteroaryl, C.sub.6-C.sub.20aroyl, C.sub.3-C.sub.20heteroarylcarbonyl or ##STR00003## or Ar.sub.1 is ##STR00004## Ar.sub.2 is for example phenylene, ##STR00005##
all of which are unsubstituted or substituted M is for example unsubstituted or substituted C.sub.1-C.sub.20alkylene Y is a direct bond, O, S, NR.sub.5 or CO; Z.sub.1 is for example O or S; Z.sub.2 is a direct bond, O, S or NR.sub.5; and Q is CO or a direct bond.

Compounds of the formulae (I) or (II) ##STR00001##
wherein X is ##STR00002## A is O, S, NR.sub.5 or CR.sub.16R.sub.17; R.sub.1 is for example hydrogen or C.sub.1-C.sub.20alkyl R.sub.2 is for example hydrogen, C.sub.1-C.sub.20alkyl or C.sub.6-C.sub.20aryl R.sub.5 for example is C.sub.1-C.sub.20alkyl; R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 for example independently of each other are hydrogen. C.sub.1-C.sub.20alkyl, halogen, CN or NO.sub.2; Ar.sub.1 is for example unsubstituted or substituted C.sub.6-C.sub.20aryl, C.sub.3-C.sub.20heteroaryl, C.sub.6-C.sub.20aroyl, C.sub.3-C.sub.20heteroarylcarbonyl or ##STR00003## or Ar.sub.1 is ##STR00004## Ar.sub.2 is for example phenylene, ##STR00005##
all of which are unsubstituted or substituted M is for example unsubstituted or substituted C.sub.1-C.sub.20alkylene Y is a direct bond, O, S, NR.sub.5 or CO; Z.sub.1 is for example O or S; Z.sub.2 is a direct bond, O, S or NR.sub.5; and Q is CO or a direct bond.

Provided is a method for producing a 2-alkylcarbonylnaphtho[2,3-b]furan-4,9-dione-related substance, which is suitable for the production on an industrial scale. The present invention provides: a method for producing an intermediate for the production of a 2-alkylcarbonyl[2,3-b]furan-4,9-dione, which comprises reacting a 1-butyne derivative in which a ketone or an alcohol is protected with a 2-hydroxy-1,4-naphthoquinone derivative having a leaving group at position-3 in a solvent in the presence of a metal or a metal compound and a base; and a substance relating to the intermediate.