The first enantioselective total synthesis of the bisanthraquinone (S)-bisoranjidiol and an unnatural regioisomer has been accomplished. Key features of the synthesis include the asymmetric oxidative biaryl coupling of a hindered 8-substituted 2-naphthol, selective para-quinone formation, and regioselective tandem Diels-Alder/aromatization reactions.

A continuous flow photopinacol coupling of benzophenone has been developed and implemented in the undergraduate laboratory. This photoreduction was accomplished using 2-propanol as an H atom donor and cosolvent in the reaction. The simple and inexpensive UV light source and flow reactor design (less than $350/photochemical flow system) provide an operationally accessible experiment. Students successfully compared the efficiencies (percentage conversion) of both flow and batch methods and explored fundamental continuous flow concepts to explain how and why continuous flow can improve the efficiency of a photochemical reaction. The percentage conversions for the flow reactions (average 82%) were more than 8 times higher than the batch reactions, based on irradiation of equal reaction volumes for 10 min.

The structure of a reported natural product isolate has been revised from (S)-2,2′-dimethoxy-[1,1′-binaphthalene]-5,5′,6,6′-tetraol to a known tetrabrominated diphenyl ether. After total synthesis of the reported binaphthalenetetrol was accomplished via a key reduction of a binaphtho-ortho-quinone, comparison of the physical properties and NMR spectroscopic data of the synthetic material indicated that the structure of the natural product isolate was incorrect. Evaluation of the authentic natural product suggested the structure is a tetrabrominated diphenyl ether, likely 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol.

The selective oxidation of a series of functionalized 8,8'-hydroxylated binaphthols to binaphtho-para- and binaphtho-ortho-quinones has been realized using either a Co-salen catalyst or ortho-iodoxybenzoic acid. A unique spirocyclic bis-spironaphthalenone was also obtained in good yield via a phenyliodonium diacetate promoted oxidative dearomatization.

An axial chiral tetrachlorinated bisbenzo[a]phenazine has been discovered that undergoes an alkane-induced shift in the solid state from a disordered amorphous form to an ordered polycrystalline form. This phase transition is caused by the formation of pores that accommodate linear alkanes of varying lengths with a very strong affinity as judged by differential scanning calorimetry. Single crystal X-ray structure analysis revealed that a series of weak phenolic OH···Cl hydrogen bonds dictates the pore structure. These weak interactions can be disrupted mechanically, causing the material to revert to the amorphous form. Notably, the interchange between the amorphous and crystalline forms is readily reversible and is easily observed by characteristic colorimetric changes. Measurements via photoimage processing reveal that the degree of color change is dictated by the type of alkane employed.

The development of the first asymmetric synthesis of a chiral anthraquinone dimer is outlined, resulting in the first total synthesis of (S)-bisoranjidiol. Rather than a biomimetic dimerization retrosynthetic disconnection, the anthracenyl ring systems are generated after formation of the axially chiral binaphthalene framework. This synthetic strategy has enabled the synthesis of several analogs. Key features of the synthesis include the enantioselective coupling of a hindered 2-naphthol containing substitution peri to the site of C-C bond formation, the regioselective oxidation of 8,8′-hydroxylated binaphthols to binaphtho-para-quinones, and a tandem regioselective Diels-Alder/aromatization reaction.

Selective Oxidation of 8,8'-Hydroxylated Binaphthols to Bis-spironaphthalenones or Binaphtho-para-and Binaphtho-ortho-quinones. -In the presence of different oxidants (O2/Co(II)-catalyst, IBX, PhI(OAc)2), the title binaphthols are converted to the quinone derivatives. In the case of binaphthols bearing unprotected 2,2'-hydroxy groups, the formation of bishemiketals is observed depending on both the solvent and the electronic nature of the 3,3'-substituents. -(PODLESNY, E. E.; CARROLL, P. J.; KOZLOWSKI*, M. C.; Org. Lett. 14 (2012) 18, 4862-4865, http://dx.

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