Di-2,2,2-trichloroethyl acetals

Protection of aldehydes and ketones. Treatment of a dimethyl or diethyl acetal with 1.5 eq. of trichloroethanoi in refluxing benzene under acid cataly.sis (p-TsOH) gives the mixed acetal use of 4 eq. of the alcohol gives the di-2,2,2-trichloroethyl acetal. 

A soln. of the startg. m. and Zn-dust in methanol refluxed 12 hrs. under argon -> dodecanal. Y 89%. - Advantages of the above protective group are efficient introduction and removal, stability toward many reagents, and selective removability. F. e. s. E. J. Corey and R. A. Ruden, J. Org. Chem. 38, 834 (1973) protection of carbonyl groups as mono- or di-2,2,2-trichloroethyl acetals cf. J. L. Isidor and R. M. Carlson, J. Org. Chem. 38, 554 (1973). 

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