Optically Pure α-(Trimethylsilyl)benzyl Alcohol: A Practical Chiral Auxiliary for Oxocarbenium Ion Reactions
摘要:
GRAPHICSEnantiopure (S)-alpha-(trimethylsilyl)benzyl alcohol (98% ee) was prepared by Noyori's transfer hydrogenation of benzoyltrimethylsilane. The corresponding trimethylsilyl ether was subjected to Marko's silyl modified Sakurai conditions with a variety of aldehydes to afford homoallylic ethers in high diastereoselectivity. The practicality of the alpha-trimethylsilyl benzyl group as an oxocarbenium ion auxiliary was further demonstrated by its efficient deprotection or conversion to a benzyl protecting group.
Optically Pure α-(Trimethylsilyl)benzyl Alcohol: A Practical Chiral Auxiliary for Oxocarbenium Ion Reactions
摘要:
GRAPHICSEnantiopure (S)-alpha-(trimethylsilyl)benzyl alcohol (98% ee) was prepared by Noyori's transfer hydrogenation of benzoyltrimethylsilane. The corresponding trimethylsilyl ether was subjected to Marko's silyl modified Sakurai conditions with a variety of aldehydes to afford homoallylic ethers in high diastereoselectivity. The practicality of the alpha-trimethylsilyl benzyl group as an oxocarbenium ion auxiliary was further demonstrated by its efficient deprotection or conversion to a benzyl protecting group.
Diastereoselective Additions of Nucleophiles to α-Acetoxy Ethers Using the α-(Trimethylsilyl)benzyl Auxiliary
作者:Scott D. Rychnovsky、Jennifer Cossrow
DOI:10.1021/ol0347904
日期:2003.6.1
the diastereoselective addition of a variety of nucleophiles to alpha-(trimethylsilyl)benzyl-substituted oxocarbenium ions. The oxocarbenium ions are generated from alpha-acetoxy ethers, which are easily prepared viareductive acetylation of esters. The alpha-(trimethylsilyl)benzyl auxiliary produces good to excellent facial selectivity with a variety of nucleophiles, including silyl enol ethers, silyl