O-Silylated Enolates - Versatile Intermediates for Organic Synthesis
作者:Jerald K. RASMUSSEN
DOI:10.1055/s-1977-24284
日期:——
Recent developments in the preparation and reactions of silyl enol ethers derived from aldehydes, ketones, and carboxylic acids and esters are discussed. These versatile compounds provide tremendous potential as synthetic enol equivalents. 1. Synthesis of Silyl Enol Ethers 1.1. Preparation from Enolates 1.2. Preparation from Hydrosilanes 1.3. Preparation from Other Silylating Agents 1.4. Preparation by Thermal Rearrangements 2. Synthesis of Ketene Silyl Acetals 2.1. Preparation from α-Anions and Dianions 2.2. Preparation by Hydrosilylation 3. Reactions of Silylated Enols 3.1. Preparation of Directed Enolates 3.2. Addition of Halides to the Double Bond 3.3. Reactions with Hydrogen Halides 3.4. Cycloaddition Reactions 3.5. Oxidation of Silyl Enol Ethers 3.6. Titanium(IV) Chloride Promoted Reactions 3.7. Thermal Rearrangements of Ketene Silyl Acetals 4. Conclusion
High Pressure Reaction of 1-Methoxy-3-trialkylsiloxybuta-1,3-diene with Aldehydes. [4 + 2] Cycloaddition or Silicon Migration Reaction
作者:Yoshinori Yamamoto
DOI:10.1246/cl.1987.945
日期:1987.5.5
The highpressurereaction of Danishefsky’s diene with aromatic aldehydes produces the [4 + 2] cycloadduct, while with an aliphatic aldehyde such as 2-phenylpropionaldehyde the intermolecular silicon migration from oxygen to oxygen takes place.