is commercially available, is a practical and useful Lewis acidcatalyst for acylation of alcohols with acidanhydrides or the esterification of alcohols by carboxylic acids in the presence of p-nitrobenzoic anhydrides. The remarkably high catalytic activity of scandium triflate can be used for assisting the acylation by acidanhydrides of not only primary alcohols but also sterically-hindered secondary
Macrolactonization Reactions Driven by a Pentafluorobenzoyl Group**
作者:Guillaume Force、Anna Perfetto、Robert J. Mayer、Ilaria Ciofini、David Lebœuf
DOI:10.1002/anie.202105882
日期:2021.9
towards their synthesis, notably from seco-acids, a macrolactonization promoter system that is effective, selective, flexible, readily available, and, insofar as possible, compatible with manifold functional groups is still lacking. Herein, we describe a strategy that relies on the formation of a mixed anhydride incorporating a pentafluorophenyl group which, due to its high electronic activation enables
Vielgliedrige heterocyclische Verbindungen VIII. Zur Kenntnis der hochgliedrigen Mono- und Poly-lȧctonringe
作者:M. Stoll、A. Rouvé
DOI:10.1002/hlca.193501801153
日期:——
1. Es wurde gezeigt, dass die der Veresterungsreaktion entgegenlaufende Verseifungsreaktion keine messbare Geschwindigkeit besitzt.
1.《世界经济日报》,《世界经济日报》。
Macrocyclisation of Macrodiolide with Dimethylaluminium Methaneselenolate
作者:Liu-Lan Shen、Han-Seo Mun、Jin-Hyun Jeong
DOI:10.1002/ejoc.201001201
日期:2010.12
Dimethylaluminium methaneselenolate (Me 2 AlSeMe, 1) acts as an acyltransferagent for esterification. In cases of direct macrolactonisation (n = 10-12), this selenium-aluminium complex preferentially creates symmetric macrodiolides rather than macrolides. The factors determining macrodilactonisation were investigated and applied toward the total synthesis of norpyrenophorin, which result in a macrodilactonisation
New and Efficient Method for the Preparation of Medium-sized Lactones from the Corresponding<i>ω</i>-Hydroxycarboxylic Acids
作者:Teruaki Mukaiyama、Jun Izumi、Isamu Shiina
DOI:10.1246/cl.1997.187
日期:1997.2
Medium-sized lactones are prepared in good yields on treating monomeric cyclic silyl siloxycarboxylates, prepared in situ from ω-hydroxycarboxylic acids and 1,2-bisdimethylsilylbenzene using RhCl(PPh3)3 catalyst, with an active catalyst of dimethylsilylbis(trifluoromethanesulfonate).