Protecting groups photosensitive

V. Zehavi, Applications of Photosensitive Protecting Groups in Carbohydrate Chemistry, Adv. Carbohydr. Chem. Biochem., 46, 179-204 (1988). 

APPLICATIONS OF PHOTOSENSITIVE PROTECTING GROUPS IN CARBOHYDRATE CHEMISTRY... 

In general, photosensitive protecting groups are removed by photosolvolysis, making use of the different reactivities of the excited and ground states, or by intramolecular, photoactivation reactions. 

The selective protection of hydroxyl groups is obviously most frequent in carbohydrate synthesis and, in fact, photosensitive protecting groups have been used to this effect in oligosaccharide synthesis, nucleotide synthesis, and saccharide modification. Here, as well as in other Sections, special attention will be devoted to 2-nitrobenzyl derivatives, whose re-... 

Photosensitive protecting groups discussed here belong to three different classes cyclic acetals, thioacetals, and hydrazones. 

Ester formation is the main and most efficient means of protecting carboxylic acids. The protection of a carboxylic acid as an amide is infrequent, as its removal normally requires drastic conditions. Most of the work concerned with the use of light-sensitive protecting-groups for carboxylic acids is in peptide synthesis. Carboxylic acids are protected as photosensitive esters, including ester linkages to polymer supports or as (difficult to prepare) photosensitive amides. Many of these techniques may be readily applied to sugar acids. 

Banerjee, A. Falvey, D. E. Protecting groups that can be removed through photochemical electron transfer mechanistic and product studies on photosensitized release of carboxyl-ates from phenacyl esters. J. Org. Chem. 1997, 62, 6245-6251. 

Barltrop, J.A., Plant, P.J. and Schofield, P. (1966) Photosensitive protective groups. Journal of the Chemical Society, Chemical Communications, 822-823. 

Patchornik, A., Amit, B. and Woodward, R.B. (1970) Photosensitive protecting groups. Journal of the American Chemical Society, 92, 6333-6335. 

Hebert, J. and Gravel, D. (1974) o-Nitrophenylethylene glycol a photosensitive protecting group for aldehydes and ketones. Canadian Journal of Chemistry, 52, 187-189. 

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