The present invention relates to methods for linking tetrazines with dienophiles to establish at least two linkages by sequentially performing at least two cycloaddition reactions. The methods in particular allow establishing multi-labeling strategies. In particular, the invention relates to methods for forming linkages by cycloaddition reactions, wherein the method comprises reacting a first alkyl-substituted tetrazine with a first dienophile comprising a irans-cyclooctenyl group followed by reacting a second tetrazine with a second dienophile comprising a cyclooctynyl group, wherein the reaction of the first tetrazine with the first dienophile proceeds in the presence of the second dienophile.

The present disclosure discloses prodrugs of gamma-hydroxybutyric acid as well as compositions and uses thereof.

The present disclosure discloses prodrugs of gamma-hydroxybutyric acid as well as compositions and uses thereof.

Disclosed are compounds of Formulas (I), (II), (III), (IV), and (V): ##STR00001##
and/or a salt thereof, wherein R.sub.1 is OH or OP(O)(OH).sub.2, and X.sub.1, X.sub.2, X.sub.3, R.sub.2, R.sub.2a, R.sub.a, R.sub.b, and R.sub.c are defined herein. Also disclosed are methods of using such compounds as selective agonists for G protein-coupled receptor S1P.sub.1, and pharmaceutical compositions comprising such compounds. These compounds are useful in treating, preventing, or slowing the progression of diseases or disorders in a variety of therapeutic areas, such as autoimmune diseases and vascular disease.

Disclosed are compounds of Formulas (I), (II), (III), (IV), and (V): ##STR00001##
and/or a salt thereof, wherein R.sub.1 is OH or OP(O)(OH).sub.2, and X.sub.1, X.sub.2, X.sub.3, R.sub.2, R.sub.2a, R.sub.a, R.sub.b, and R.sub.c are defined herein. Also disclosed are methods of using such compounds as selective agonists for G protein-coupled receptor S1P.sub.1, and pharmaceutical compositions comprising such compounds. These compounds are useful in treating, preventing, or slowing the progression of diseases or disorders in a variety of therapeutic areas, such as autoimmune diseases and vascular disease.

The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

The present disclosure discloses prodrugs of gamma-hydroxybutyric acid as well as compositions and uses thereof.

The present disclosure discloses prodrugs of gamma-hydroxybutyric acid as well as compositions and uses thereof.