ChemInform Abstract: Asymmetric Synthesis of Functionalized Secondary Alcohols by Catalytic Ring-Cleavage Reactions of Cyclic Acetals Derived from (R)-1,3- Butanediol.

✍ Scribed by M. KINUGASA; T. HARADA; T. EGUSA; K. FUJITA; A. OKU

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 38 KB
• Volume: 28
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199715039

✦ Synopsis

Asymmetric Synthesis of Functionalized Secondary Alcohols by Catalytic Ring-Cleavage Reactions of Cyclic Acetals Derived from (R)-1,3-Butanediol.

-Optically active B-phenyloxazaborolidinones derived from sulfonamides of α-amino acids are shown to be efficient catalysts for the cleavage of cyclic acetals from aromatic, aliphatic and α,β-unsaturated aldehydes with nucleophiles derived from enol silyl ethers, silanes or organotin compounds. The reaction proceeds with inversion at the acetal carbon leading to the anti isomers (III), (VI), (X), ( XIII), or (XV). Removal of the chiral auxiliary gives enantiomerically enriched β-hydroxy carbonyl compounds such as (IV), (VII), or (XI) . -(KINUGASA, M.; HARADA,