The present invention relates to a process for preparing at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group, at least comprising the stages:
(a1) oxidation of a composition (A), at least comprising one cyclic olefin with Z cycles and 7 to 16 carbon atoms and at least two C—C double bonds, by means of dinitrogen monoxide to give a composition (A1),
(a2) separating off the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms with at least two C—C double bonds from the composition (A1) in order to obtain a composition (A2), and
(b) distillative treatment of the composition (A2) from step (a2) in order to obtain a composition (B), comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group and
less than 1.0% by weight of the at least one compound with Z−1 cycles and 7 to 16 carbon atoms with at least one aldehyde group,
where Z can be 1, 2, 3 or 4.
When |8|(2,5)thiophenophane (4) is treated with an excess of t-BuCl/SnCl4 in CS2 at room temperature, a deepseated rearrangement occurs, t-butyl groups are introduced into the 2- and 5-position of the thiophene nucleus with a concomitant migration of the octamethylene bridge to the 3- and 4-position. In addition to the di-t-butylthiophene (8), two mono-t-butylthiophenes (14 and 16) are formed under
Diradical-Promoted (<i>n </i>+ 2 − 1) Ring Expansion: An Efficient Reaction for the Synthesis of Macrocyclic Ketones
作者:Georg Rüedi、Matthias A. Oberli、Matthias Nagel、Hans-Jürgen Hansen
DOI:10.1021/ol048701e
日期:2004.9.1
[reaction: see text] A diradical-promoted (n + 2 - 1) ringexpansionreaction based on vinyl side chain insertion (+2C) and decarbonylation (-1C) has been developed. Flash vacuum pyrolysis (FVP) of medium- and large-ring 2-trimethylsilyloxy-2-vinyl-cycloalkanones at 500-600 degrees C affords the one-carbon ring-expanded cycloalkanones in good yields. Methyl groups on the vinyl moiety are transformed
Preparation of 1,4-Cycloalkanediones by Hypoiodite Oxidation of Cycloalkanols
作者:Takasi Mori、Kiyohide Matsui、Hitosi Nozaki
DOI:10.1246/bcsj.43.231
日期:1970.1
Lead tetraacetate oxidation of 11, 12 and 13-membered cycloalkanols gives improved yields of 2,5-polymethylenetetrahydrofurans II in the presence of iodine. Oxidative cleavage of II furnishes 1,4-cycloalkanediones VII.
在碘存在下,11、12 和 13 元环烷醇的四乙酸铅氧化提高了 2,5-聚亚甲基四氢呋喃 II 的产率。II 的氧化裂解提供 1,4-环烷二酮 VII。
Synthesis of some medium- and large-ring cycloalk-2-ene-1,4-diones by intramolecular coupling of αω-bis-diazoketones
作者:Sunanta Kulkowit、M. Anthony McKervey
DOI:10.1039/c39780001069
日期:——
In the presence of Cu(acac)2(Hacac = acetylacetone) someαω-bis-diazoketones couple intramolecularly with loss of nitrogen giving cycloalk-2-ene-1,4-diones; the enediones can be converted into fused ring cyclopentenones by successive treatment with sodium dithionite and sodium hydroxide.