Synthese von verbrückten derivaten des tetra-tert. Butylethens
作者:Adolf Krebs、Wolfgang Rüger、Wolf-Ulrich Nickel
DOI:10.1016/s0040-4039(01)92386-x
日期:1981.1
The sterically hindered alkenes and , which are potential precursors for the synthesis of tetra-tert.butylethene, were prepared. Attempts at the synthesis of via the thiadiazoline route failed.
制备了位阻链烯烃和,它们是合成四叔丁基乙烯的潜在前体。通过噻二唑啉路线合成的尝试失败。
Geminal Acylation with Methyl-Substituted Analogues of 1,2-Bis[(trimethylsilyl)oxy]cyclobutene
作者:Sheldon N. Crane、Tracy J. Jenkins、D. Jean Burnell
DOI:10.1021/jo971055v
日期:1997.12.1
BF3 . Et2O-catalyzed geminal acylation of ketones and acetals with 3-methyl-1,2-bis[(trimethylsilyl)oxy)]cyclobutene (3) provided methylcyclopentanediones in yields that ranged from 40 to 94%. The best substrates were unhindered cyclohexanones. With acetals, stereochemical preferences in the initial Mukaiyama-like aldol step giving cyclobutanones translated into the stereochemistry of the ultimate cyclopentanedione products. With ketones, equilibration of the initial cyclobutanone compounds resulted in cyclopentanedione products with a different stereochemical preference. The gem-dimethylcyclobutene reagent 4 reacted with ketones to give gem-dimethylcyclopentanediones in modest yield. The process was much more stereochemically efficient than the reaction with 3. Rearrangement from the initial cyclobutanone compound was partially diverted toward air-sensitive 3-furanone compounds and ring-opened 1,2-diones. Only furanones (e.g., 52 and 53) were isolated from reactions with the tetramethylcyclobutene 51.
Le Peletier de Rosanbo, Annales de Chimie (Cachan, France), 1923, vol. <9> 19, p. 342
作者:Le Peletier de Rosanbo
DOI:——
日期:——
Geminal Acylation of Ketones Mediated by Boron Trichloride. An Improved Method for the Synthesis of 4,4-Dimethyl-1,3-cyclopentanediones
作者:Sheldon N. Crane、D. Jean Burnell
DOI:10.1021/jo9806308
日期:1998.8.1
KREBS, A.;RUEGER, W.;NICKEL, W. -U., TETRAHEDRON LETT., 1981, 22, N 49, 4937-4940