Photochemical para Rearrangement of Phenyl Ethers

REACTIONS OF ATOMS AND FREE RADICALS IN SOLUTION. XXV. THE REACTIONS OF OLEFINS WITH MERCAPTANS IN THE PRESENCE OF OXYGEN1

“…Concerning over-all mercaptan-styrene additions it has been established that the relative reaction rates follow the order: ArylSH > H02CCH2SH > > RCH2SH > RR'CHSH > RR'R"CSH, which is the same order observed for corresponding rates of mercaptan oxidation by a variety of oxidants (3).…”

“…It is noteworthy that when styrene-mercaptan addition experiments are conducted in the absence of oxygen, even when equimolecular quantities of olefin and mercaptan are used, there is a considerable yield of product containing two molecules of hydrocarbon per molecule of mercaptan, together with a high-boiling residue with a hydrocarbon-mercaptan ratio greater than two to one. 3 These observations indicate that for the reactant pairs investigated type reaction 4, and even type reactions 5 and 6, are favored over type reaction 3. In heptane solution and in the presence of oxygen as the sole oxidant, neither the usual one-to-one styrene-mercaptan addition product nor any product containing more than one molecule of olefin per molecule is formed. It may therefore be inferred that type reaction 10 is favored over both type reactions 3 and 4.…”

Heteroatom directed photoarylation. Synthetic potential of the heteroatom oxygen

“…Caled for C16H20O3: C, 73.82; H, 7.74; O, 18.44. Found: C, 73.74; H, 7.76. 2-(p-Methoxyphenoxy)-3,5,5-trimethyI-2-cyclohexen-l-one (5d) was prepared from p-methoxyphencl and epoxide 4 (89%, bp 126-129 °C at 0.15 mm; crystallized on standing, mp 44-45 °C); NMR gave singlets at 1.12 (6 H) and 6.80 (4 H); IR (chloroform) 5.95, 6.08, 6.20, and 6.28 µ. 2-(o-Methylphenoxy)-3,5,5-trimethyl-2-cyclohexen-l-one (5e) was prepared from o-cresol and epoxide 4 (91%, bp 109-112 °C at 0.10 mm); >H NMR gave singlets at 1.13 ( 6), 1.88 (3 H), 2-(m-Methylphenoxy)-3,5,5-trimethyl-2-cyclohexen-l-one (5f) was prepared from w-cresol and epoxide 4 and crystallized from etherpetroleum ether (86%, mp 57-58 °C);…”

“…la, R = H (morphine) b, R = CH3 (codeine) OCH3 3 A complete review of aryl ether photochemistry will not be attempted here;4 we will note, however, that at the outset of this work, reported photoreactions of aryl ethers consisted of cleavage of the ether bond(s) followed by hydrogen abstraction from solvent to give phenols and photorearrangement to give orthoand para-substituted hydroxybiphenyls. 5 Photocycli-zation-elimination of ortho-substituted diaryl ethers had been accomplished in low to moderate yield;6 more recently, the oxidative photocyclization of diphenyl ether to dibenzofuran has been reported. 7 Careful considerations of reported aryl ether photochemistry and the efficiency of dihydrothiophene formation from 2-thioaryloxyenones3 suggested that our studies should begin with the photochemistry of 2-aryloxyenones.…”

Mechanistic study of the photo-Fries rearrangement of phenyl acetate

“…If 6 were being formed, it might tautomerize to 7 before resulting in p-OHA. The cal-Journal of the American Chemical Society / 96:2 / January23, 1974…”