... Several reaction samples of protection and deprotection are shown for each groups. Aldehyde dehydrogenase (ALDH) enzymes catalyze the NAD(P) +-dependent oxidation of a wide variety of endogenous and exogenous aldehydes to their corresponding acids. Orthogonal protection is a strategy allowing the specific deprotection of one protective group in a multiply-protected structure without affecting the others. Some strong oxidation agents may cleave acetals such as HClO 4 in CH 2 Cl 2. In this discussion let us focus on the classes of protecting groups rather than an exhaustive treatment of all the protections. For example, the amino acid tyrosinecould be protected as a benzyl ester on the carboxyl group, a fluorenylmethylenoxy carbamate on the amine group, and a tert-butyl ether on the phenol group. All of theses reactions are taken from our synthesis database and the list is continually growing. In this discussion let us focus on the classes of protecting groups rather than an exhaustive treatment of all the protections. Can be deprotected in the presence of ketals and can survive ketal deprotection T. W. Green, P. G. M. Wuts, Protective Groups in Organic Synthesis, Wiley-Interscience, New York, 1999, 297-304, 724-727. Protective Groups in Organic Synthesis, Wiley-Interscience, New York, 1999, 308 ... Deprotection is often performed by acid catalyzed transacetalization in acetone or hydrolysis in wet solvents or in aqueous acid. Considered to be corneal and lens crystallins, they confer protective and transparent … Acetals are the protecting groups for aldehydes and ketones. Since alcohols, aldehydes and ketones are the most frequently manipulated functional groups in organic synthesis, a great deal of work has appeared in their protection / deprotection strategies. Perchloric acid adsorbed on silica gel is an extremely efficient, inexpensive, and reusable catalyst for the protection of aldehydes and ketones and the subsequent deprotection. Protection of Aldehyde, Ketone Thio-acetal protection • 1,3-Dithiane • 1,3-Dithiolane • S, S'-dialkyl acetals serve as an umpolung synthon in the construction of carbon-carbon bonds. The benzyl ester can be removed by hydrogenolysis, the fluorenylmethylenoxy group (Fmoc) by bases (such as piperidine), and the phenolic tert-butyl ether clea… Protection of Aldehydes and Ketones. Protection of Aldehyde, Ketone . List of protecting groups with many examples of protection and deprotection. Since alcohols, aldehydes and ketones are the most frequently manipulated functional groups in organic synthesis, a great deal of work has appeared in their protection / deprotection strategies. Some members of the ALDH superfamily of enzymes are abundantly expressed in the mammalian cornea and lens in a taxon-specific manner. Acetals as Protecting Groups for Aldehydes and Ketones. Protection of Aldehyde, Ketone Trimethylsilyl cyanohydrin protection 43. Acetalization was mostly carried out under solvent-free conditions with trialkyl orthoformates, but weakly electrophilic carbonyl compounds and substrates that can coordinate with the catalyst, required the corresponding alcohol …