- A facile synthesis of naturally occurring binaphthoquinones: Efficient oxidative dimerization of 4-alkoxy-1-naphthols using silver(II) oxide-40% nitric acid
-
Oxidation of 4-alkoxy-1-naphthols with AgO-40% HNO3 occurred along with a dimerization to give the corresponding bi-1,4-naphthoquinones. The oxidative dimerization required one hydroxyl group and took place at its ortho position. This reaction was applicable to syntheses of naturally occurring binaphthoquinones, bivitamin K3 and 3,3′-bijuglone.
- Tanoue, Yasuhiro,Sakata, Kazunori,Hashimoto, Mamoru,Morishita, Shin-Ich,Hamada, Moritsugu,Kai, Norihisa,Nagai, Takeshi
-
-
- Anodic oxidation of 4-methoxy-1-naphthol
-
Anodic oxidation of 4-methoxy-1-naphthol 1 in the presence of nucleophiles provided the corresponding products 8-12 and the dimers 13 and 17 were also produced. The reaction mechanism of the oxidation reaction including the [3+2] cycloaddition was investigated.
- El-Seedi, Hesham R.,Yamamura, Shosuke,Nishiyama, Shigeru
-
p. 3301 - 3304
(2007/10/03)
-
- Reactivity of naphthol towards nucleophiles in anodic oxidation
-
Reactivity of the anodic oxidation of 4-methoxy-1-naphthol 1 in the presence of nucleophiles has been investigated. The reaction with electron-rich alkenic nucleophiles such as 1-methoxy-4-propenylbenzene 2 and isosafrole 3 gave a very high yield, whereas the reaction with dihydropyran 4 and dihydrofuran 5 gave a moderate yield, but with ethyl vinyl ether 6 gave a very low yield of the substituted dihydronaphthofuran derivatives 7-10 and 12, respectively. Unexpectedly, the glycosyl derivative 11 was preferentially produced rather than naphthofuran 10 upon using 5 as a nucleophile. In addition, the dimers 15 and 16 were obtained in moderate yield without addition of nucleophile to 1. The mechanism of the oxidation reactions including the [3+2] and [5+2] cycloaddition were discussed.
- El-Seedi, Hesham R,Yamamura, Shosuke,Nishiyama, Shigeru
-
p. 7485 - 7489
(2007/10/03)
-
- Further Conversions of Naphthoquinones into Dinaphthofuranquinones
-
1,4-Naphthoquinone is in part converted by aluminium chloride in carbon disulphide into the ortho-quinone (3; R = H).Thermal isomerisation of the binaphthyldiquinone (1) in 2-methoxynaphthalene gives the hydroxyquinone (4; R = H) but in 1-nitronaphthalene produces the dihydroxydiquinone (7; R = H).
- Buchan, Robert,Musgrave, Oliver C.
-
-