Lewis Acid Catalyzed Geminal Acylation Reaction of Ketones with 1,2-Bis[(trimethylsilyl)oxy]cyclobutene: Direct Formation of 2,2-Disubstituted 1,3-Cyclopentanediones
摘要:
Ketones reacted with 1,2-bis((trimethylsilyl)oxy)cyclobutene (1) under catalysis by boron trifluoride etherate to yield 2,2-disubstituted 1,3-cyclopentanedione products via silylated cyclobutanone intermediates in a two-step, one-pot process. In many instances addition of a small amount of water to the reaction medium after completion of the first step assisted the subsequent rearrangement to the product, such that reversion of the intermediate to the starting ketone became an insignificant process. Yields were best with cyclohexanones (>90%), but steric hindrance and conjugated double bonds reduced yields considerably.
Facial selectivity in nucleophilic reactions of spirocyclic ketones can be controlled by a distant, orthogonal double bond
作者:Pei-Ying Liu、D. Jean Burnell
DOI:10.1039/c39940001183
日期:——
Spiro[4.5]dec-7-ene-1,4-dione and derivatives substituted at C-7, C-8, and/or C-9 gave products of reaction with methyllithium and with sodium borohydride that in every instance favoured nucleophilic carbonyl attack on the face syn to the double bond; the results are consistent with stereoelectronic control, and the selectivity correlates with a difference in the abilities of the orthogonal C–C bond to donate electron density.
Elliott, Christine E.; Miller, David O.; Burnell, D. Jean, Journal of the Chemical Society. Perkin Transactions 1 (2001), 2002, vol. 2, # 2, p. 217 - 226
作者:Elliott, Christine E.、Miller, David O.、Burnell, D. Jean
DOI:——
日期:——
Lewis Acid Catalyzed Geminal Acylation Reaction of Ketones with 1,2-Bis[(trimethylsilyl)oxy]cyclobutene: Direct Formation of 2,2-Disubstituted 1,3-Cyclopentanediones
作者:Tracy J. Jenkins、D. Jean Burnell
DOI:10.1021/jo00085a041
日期:1994.3
Ketones reacted with 1,2-bis((trimethylsilyl)oxy)cyclobutene (1) under catalysis by boron trifluoride etherate to yield 2,2-disubstituted 1,3-cyclopentanedione products via silylated cyclobutanone intermediates in a two-step, one-pot process. In many instances addition of a small amount of water to the reaction medium after completion of the first step assisted the subsequent rearrangement to the product, such that reversion of the intermediate to the starting ketone became an insignificant process. Yields were best with cyclohexanones (>90%), but steric hindrance and conjugated double bonds reduced yields considerably.
Enantio- and diastereoselectivity in the reduction of spiro[4.5]decane-1,4-dione derivatives with baker's yeast
作者:Yan-Yi Zhu、D. Jean Burnell
DOI:10.1016/0957-4166(96)00430-2
日期:1996.11
Reductions mediated by baker'syeast were carried out on five spiro[4.5]decane-1,4-dione derivatives 4, 9, 12, 15, and 18. Enantioselectivity was always very high, but this did not correlate with the facial diastereoselectivity, which ranged from very high to zero. In some instances, the facial selectivity of the yeast-mediated reduction was lower than that of NaBH4. The reduction product of 4 was