Novel photo-rearrangement of 1,5-di(p-methoxyphenyl)-6,7-dioxabicyclo[3.2.2]nonane through an O-neophyl-type 1,2-aryl shift: evidence for a 1,6-dioxyl diradical intermediate
作者:Masaki Kamata、Ken-ichi Komatsu
DOI:10.1016/s0040-4039(01)01973-6
日期:2001.12
Photolysis and thermolysis of 1,5-diaryl-6,7-dioxabicyclo[3.2.2]nonane 1a–c (a: Ar=p-MeOC6H4, b: Ar=p-MeC6H4, c: Ar=Ph) were investigated. (p-Methoxyphenyl)-substituted 1a underwent a novel photo-initiated O-neophyl-type 1,2-aryl shift to afford 1-(p-methoxyphenyl)oxy-5-(p-methoxyphenyl)-8-oxabicyclo[3.2.1]octane 7a along with a small amount of 1-(p-methoxyphenyl)-3-(2-(4′-methoxyphenyl)tetrahydro
1,5-二芳基-6,7-二氧杂双环[3.2.2]壬烷1a – c(a:Ar = p -MeOC 6 H 4,b:Ar = p -MeC 6 H 4,c:Ar的光解和热解= Ph)进行了调查。(对-甲氧基苯基)-取代的1a进行新的光引发的O-新叶型1,2-芳基转移,得到1-(对-甲氧基苯基)氧基-5-(对甲氧基苯基)-8-氧杂双环[3.2。 1]辛烷7a和少量1-(p-甲氧基苯基)-3-(2-(4'-甲氧基苯基)四氢呋喃-2-基)丙-1-酮4a通过1,6-二氧基双自由基中间体形成,而热解主要得到1,5-di(p -甲氧基苯基)戊-1,5-二酮5a和1,4-二(对甲氧基苯基)丁-1,4-二酮8a。