Organic Chemistry Portal



Room Temperature Intramolecular Hydro-O-alkylation of Aldehydes: sp3 C-H Functionalization via a Lewis Acid Catalyzed Tandem 1,5-Hydride Transfer/Cyclization

Stefan J. Pastine and Dalibor Sames*

*Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, Email:

S. J. Pastine, D. Sames, Org. Lett., 2005, 7, 5429-5431.

DOI: 10.1021/ol0522283 (free Supporting Information)

see article for more reactions


An intramolecular hydro-O-alkylation of aldehydes leads to spiroketals, bicyclic ketals, and aminals. Tertiary and sterically hindered secondary sp3 C-H bonds are transformed into C-O bonds under the action of a catalytic amount of a variety of Lewis acids. The mechanism probably involves a tandem hydride transfer/cyclization sequence.

see article for more examples

proposed mechanism

Key Words

Acetals, Lactols, Cyclization

ID: J54-Y2005-1970