A Mild PPTS-Catalyzed Acetalization of α,β-Unsaturated Aldehydes: The First Single-Step Protocol towards Benzylic Acetals
摘要:
A mild and convenient procedure for the synthesis of highly sensitive benzylic acetals from alpha,beta-unsaturated aldehydes and the corresponding benzylic alcohols is reported. The new method provides a single-step access to these compounds for the first time. The applications of pyridinium p-toluenesulfonate (PPTS) as a very mild Bronsted acid catalyst and 5 angstrom molecular sieves (MS) as the dehydrating agent were found to be essential. Furthermore, an application of the acetals in the synthesis of 1-functionalized dienes is exemplified.
A Mild PPTS-Catalyzed Acetalization of α,β-Unsaturated Aldehydes: The First Single-Step Protocol towards Benzylic Acetals
作者:Jörg Pietruszka、Dietrich Böse、Marvin Lübcke
DOI:10.1055/s-0032-1318169
日期:——
A mild and convenient procedure for the synthesis of highly sensitive benzylic acetals from alpha,beta-unsaturated aldehydes and the corresponding benzylic alcohols is reported. The new method provides a single-step access to these compounds for the first time. The applications of pyridinium p-toluenesulfonate (PPTS) as a very mild Bronsted acid catalyst and 5 angstrom molecular sieves (MS) as the dehydrating agent were found to be essential. Furthermore, an application of the acetals in the synthesis of 1-functionalized dienes is exemplified.
<i>syn</i>-Selective Kobayashi Aldol Reaction Using Acetals
作者:Hiroyuki Tsukada、Yuki Mukaeda、Seijiro Hosokawa
DOI:10.1021/ol303519y
日期:2013.2.1
The Kobayashi aldol reaction has been used to construct anti-aldol products by remote stereoinduction. Since the product of the Kobayashi aldol reaction has a typical polyketide structure, this reaction has been applied to the total synthesis of natural products. By varying this reaction, it was found that the reaction with acetals in the presence of Lewis acid proceeded to give syn adducts in high