Rapid, One-Pot Synthesis of β-Siloxy-α-haloaldehydes
摘要:
The Mukaiyama cross-aldol reaction of alpha-fluoro-, alpha-chloro-, and alpha-bromoacetaldehyde-derived (Z)tris(trimethylsilyl)silyl enol ethers is described, furnishing anti-beta-siloxy-alpha-haloaldehydes. A highly diastereoselective, one-pot, sequential double-aldol process is developed, affording novel beta,delta-bissiloxy-alpha,gamma-bishaloaldehydes. Reactions are catalyzed by C(6)F(5)CHTf(2) and C(6)F(5)CTf(2)AlMe(2) (0.5-1.5 mol %) and provide access to halogenated polyketide fragments.
Rapid, One-Pot Synthesis of β-Siloxy-α-haloaldehydes
摘要:
The Mukaiyama cross-aldol reaction of alpha-fluoro-, alpha-chloro-, and alpha-bromoacetaldehyde-derived (Z)tris(trimethylsilyl)silyl enol ethers is described, furnishing anti-beta-siloxy-alpha-haloaldehydes. A highly diastereoselective, one-pot, sequential double-aldol process is developed, affording novel beta,delta-bissiloxy-alpha,gamma-bishaloaldehydes. Reactions are catalyzed by C(6)F(5)CHTf(2) and C(6)F(5)CTf(2)AlMe(2) (0.5-1.5 mol %) and provide access to halogenated polyketide fragments.
β-Siloxy-α-haloketones through Highly Diastereoselective Single and Double Mukaiyama Aldol Reactions
作者:Jakub Saadi、Hisashi Yamamoto
DOI:10.1002/chem.201204493
日期:2013.3.18
Double‐action haloketones: A super silyl group enabled the first highlydiastereoselectiveMukaiyamaaldolreactions of α‐chloro‐ and α‐fluoroketones with a wide range of aldehydes, providing anti‐β‐siloxy‐α‐haloketones. This process is compatible with one‐pot double‐aldol methodology and allows for rapid access to new halogen‐modified polyketide fragments bearing up to four contiguous stereocenters