Photochemical Synthesis of Chrysenols

Abstract

Chrysenols are formed together with other metabolites when chrysene is metabolized in living organisms. The principal metabolites are needed as pure compounds for reference materials and standards to study various aspects of this metabolism. In this study the 1-, 2-, 3-, and 4-chrysenols have been made in pure form by photochemical ring closure of [(methoxyphenyl)vinyl]naphthalene to the methoxychrysenes followed by deprotection, and purification of the chrysenols. The method may be applied to make the single pure compounds in high yields.

Substituted Two- to Five-Ring Polycyclic Aromatic Compounds Are Potent Agonists of Atlantic Cod (Gadus morhua) Aryl Hydrocarbon Receptors Ahr1a and Ahr2a

“…The PAHs chrysene (CHR), 5-methylchrysene (5-MC), phenanthrene (PHE), naphthalene (NAP), pyrene (PYR), benzo[ a ]pyrene (BAP), fluorene (FLU), (1 R ,2 R )-1,2-dihydronaphthalene-1,2-diol ( R , R -1,2-DHN), and dibenzothiophene (DBT) were purchased from Merck KGaA (Darmstadt, Germany). The synthesis of (1 R ,2 R )-1,2-dihydrophenanthrene-1,2-diol ( R , R -1,2-DHP), 11 1-,2-,3-,4-methoxychrysene (1-,2-,3-,4-MOC) and chrysene-1- ol ,-2- ol ,-3- ol ,-4- ol (1-,2-,3-,4-COH), 41 1-,2-,3-,4-,6-methylchrysene (1-,2-,3-,4-,6-MC), 42 3-ethylphenanthrene (3-EP), and 3-propylphenanthrene (3-PP) 43 is described elsewhere. 1,7-, 2,3-, and 2,7-dimethylphenanthrene (1,7-, 2,3-, and 2,7-DMP) were prepared as described by Böhme et al, 44 and the preparation of 2,3-dimethoxychrysene (2,3-DMOC) is described in the Supporting Information .…”

Photochemical Oxidative Cyclisation of Stilbenes and Stilbenoids—The Mallory-Reaction

“…This is illustrated in some patents [ 20 , 21 , 22 ] describing a photocyclization with 5 g starting material per liter of solvent. Also in our experience this is about the concentration limit to avoid significant side reactions under Katz-conditions [ 23 ]. Reaction times depend on concentrations, but Katz’s conditions are often faster than using catalytic amounts of iodine [ 24 ].…”

“… [ 81 ] I 2 , Methyloxirane, Toluene, hν = ? [ 82 ] I 2 , Methyloxirane, Benzene, hν = 40 h [ 83 ] I 2 , Methyloxirane, Light petroleum, hν = 2 h [ 84 ] I 2 , Epoxybutane, Toluene, hν = 1.5 h [ 23 ] I 2 , Epoxybutane, Benzene, hν = 2 h [ 85 ] I 2 , Methyloxirane, Cyclohexane, hν = 50 h [ 86 ] I 2 , Epoxybutane, Benzene, hν = 8 h …”

Directedortho-Metalation and Anionicortho-Fries Rearrangement of Polycyclic AromaticO-Carbamates: Regioselective Synthesis of Substituted Chrysenes

“…To initiate the study, we used the photochemical oxidative cyclization of stilbenes to chrysenes, − which has proven to be a reliable workhorse in the preparation of methoxychrysenes. The thus prepared methoxychrysenes, upon deprotection with BBr 3 , furnished 1- and 3- chrysenols 1a (96%) and 1c (98%) in good to excellent yields (Scheme ) which, upon deprotonation with NaH and trapping with N,N -diethyl carbamoyl chloride, afforded the O -carbamoyl chrysenes 2a and 2c in 95% and 91% yield, respectively (Scheme a).…”

“…Chrysenols 1a−1c were synthesized by oxidative photocyclization of stilbenes followed by demethylation with BBr 3 , as previously described. 34 General Procedure for the Synthesis of Chrysenyl N,N-Diethyl-O-carbamate from Chrysenols. The chrysenol (1 mmol) in THF (2 mL) was added to a suspension of NaH (1.2 mmol) in THF (2 mL) at 0 °C.…”