Nucleophile-dependent substitution reactions of 5-halovaleric acid esters: synthesis of 6,12-dioxamyristic acid
摘要:
The reaction of 5-ethoxypentan-1-ol with a variety of 5-halovalerate alkyl esters afforded ester exchange products rather than the expected products of Williamson ether synthesis. The virtually unknown reaction of an alkoxide with a 5-halovalerate ester contrasts strongly with literature reports of reactions involving other nucleophiles in which the halogen substitution products are nearly always isolated. An explanation is offered for this behavior in terms of a chelation-induced conformation of the substrate. Although the direct synthetic approach failed, the hitherto unknown title compound could still be prepared, albeit in six steps in 6% overall yield. The approach used is discussed along with the interesting chemistry of this system.
Nucleophile-dependent substitution reactions of 5-halovaleric acid esters: synthesis of 6,12-dioxamyristic acid
摘要:
The reaction of 5-ethoxypentan-1-ol with a variety of 5-halovalerate alkyl esters afforded ester exchange products rather than the expected products of Williamson ether synthesis. The virtually unknown reaction of an alkoxide with a 5-halovalerate ester contrasts strongly with literature reports of reactions involving other nucleophiles in which the halogen substitution products are nearly always isolated. An explanation is offered for this behavior in terms of a chelation-induced conformation of the substrate. Although the direct synthetic approach failed, the hitherto unknown title compound could still be prepared, albeit in six steps in 6% overall yield. The approach used is discussed along with the interesting chemistry of this system.
Amphiphilic Organocatalyst for Schotten-Baumann-Type Tosylation of Alcohols under Organic Solvent Free Condition
作者:Keisuke Asano、Seijiro Matsubara
DOI:10.1021/ol900125y
日期:2009.4.16
A Tosylation of primary alcohol with tosyl chloride was performed effectively with an N-hexadecylimidazole catalyst in water containing K2CO3. aggregation of the catalyst carrying a hydrophobic methylene chain worked as a substitute for organic solvent.
N-十六烷基咪唑催化剂可在含K 2 CO 3的水中有效地进行伯醇与甲苯磺酰氯的甲苯磺酸酯化反应。带有疏水性亚甲基链的催化剂的聚集体用作有机溶剂的替代物。
KATOH, AKIRA;LU, TIANBAO;DEVADAS, B.;ADAMS, STEVEN P.;GORDON, JEFFREY I.;+, J. ORG. CHEM., 56,(1991) N, C. 731-735
作者:KATOH, AKIRA、LU, TIANBAO、DEVADAS, B.、ADAMS, STEVEN P.、GORDON, JEFFREY I.、+