The present invention relates inter alia to a compound of formula (I)

##STR00001##

wherein R.sub.1, R.sub.2 and R.sub.3, are as defined in the specification and to compositions comprising the same and to the use of the compounds and to compositions of the compounds in treatment, for example in the treatment of fibrotic diseases or interstitial lung diseases, in particular idiopathic pulmonary fibrosis.

The invention includes procedures for stereoselective β-acylation of carboxylic acids having a β-carbon atom. For example, stereoselective acylation procedures include the following reactions: (I) ##STR00001##

The invention includes procedures for stereoselective β-acylation of carboxylic acids having a β-carbon atom. For example, stereoselective acylation procedures include the following reactions: (I) ##STR00001##

The general inventive concepts are directed to the discovery that certain aryl acids can be esterified under particular conditions to provide the resulting ester as a solid that precipitates in good yield from the reaction mixture. The esters may then be isolated and purified with relative ease. Accordingly, a method for the esterification, isolation, and purification of aryl acids is provided.

The general inventive concepts are directed to the discovery that certain aryl acids can be esterified under particular conditions to provide the resulting ester as a solid that precipitates in good yield from the reaction mixture. The esters may then be isolated and purified with relative ease. Accordingly, a method for the esterification, isolation, and purification of aryl acids is provided.

The invention includes procedures for stereoselective -acylation of carboxylic acids having a -carbon atom. For example, stereoselective acylation procedures include the following reactions: (I)

##STR00001##

The invention includes procedures for stereoselective -acylation of carboxylic acids having a -carbon atom. For example, stereoselective acylation procedures include the following reactions: (I)

##STR00001##

The present invention provides a process for purifying a monoterpene or sesquiterpene having a purity greater than about 98.5% (w/w). The process comprises the steps of derivatizing the monoterpene (or sesquiterpene) to produce a monoterpene (or sesquiterpene) derivative, separating the monoterpene (or sesquiterpene) derivative, and releasing the monoterpene (or sesquiterpene) from the derivative. Also encompassed by the scope of the present invention is a pharmaceutical composition comprising a monoterpene (or sesquiterpene) having a purity greater than about 98.5% (w/w). The purified monoterpene can be used to treat a disease such as cancer. The present monoterpene (or sesquiterpene) may be administered alone, or may be co-administered with radiation or other therapeutic agents, such as chemotherapeutic agents.

The present invention provides a process for purifying a monoterpene or sesquiterpene having a purity greater than about 98.5% (w/w). The process comprises the steps of derivatizing the monoterpene (or sesquiterpene) to produce a monoterpene (or sesquiterpene) derivative, separating the monoterpene (or sesquiterpene) derivative, and releasing the monoterpene (or sesquiterpene) from the derivative. Also encompassed by the scope of the present invention is a pharmaceutical composition comprising a monoterpene (or sesquiterpene) having a purity greater than about 98.5% (w/w). The purified monoterpene can be used to treat a disease such as cancer. The present monoterpene (or sesquiterpene) may be administered alone, or may be co-administered with radiation or other therapeutic agents, such as chemotherapeutic agents.

Disclosed is the use of the reactive components of the inverse electron-demand Diels Alder reaction for chemical masking and unmasking in vitro. This can be applied in complex chemical reactions and, particularly in the synthesis of biomolecules, e.g. on solid supports. The reactice components are a dienophile, particularly a trans-cyclooctene, and a diene, particularly a tetrazine.