Abstract: A novel class of protecting compounds, particularly for amino acids, is based on 2,2 di nitrophenyl ethan- groups, particularly the groups wherein the nitro is in the para position. The ethyl group may be substituted, e.g. by an alkyl group, in the l- position. Preferred compounds include the alcohol or halide which are suitable for protecting acid functional groups, and esters, including activated and substituted esters, particularly the succinimidyl ester, for protecting amine groups. The invention includes methods of manufacture and use, together with protected amino acids.

Abstract: A class of novel chemical compounds comprising derivatives of 2,2,5,7,8-pentamethylchroman-6-sulphonyl and having the structural formula ##STR1## wherein X is selected from halogen and other groups having acidic functionality. We prefer that the X-group be chlorine.The said compounds are made by the sulphonation of 2,2,5,7,8-pentamethylchroman, preferably using chlorosulphonic acid.The primary utility of the compounds of the present invention is in the protection of functional groups in organic synthesis and more particularly in the protection of basic functional amino groups, such as amidines and guanidines.The invention also provides a method of making the protecting group and a protected amino acid.

Abstract: A class of novel chemical compounds comprising derivatives of 2,2,5,7,8-pentamethylchroman-6-sulphonyl and having the structural formula ##STR1## wherein X is selected from halogen and other groups having acidic functionality. We prefer that the X-group be chlorine.The said compounds are made by the sulphonation of 2,2,5,7,8-pentamethylchroman, preferably using chlorosulphonic acid.The primary utility of the compounds of the present invention is in the protection of functional groups in organic synthesis and more particularly in the protection of basic functional amino groups, such as amidines and guanidines.The invention also provides a method of making the protecting group and a protected amino acid.