abstract |
The present invention relates to compounds which are useful for efficient synthesis of 2-amino-4-oxobicycloÄ3.1.0Ühexane-2,6-dicarboxylic acids. The compounds according to the present invention comprise 2-oxobicycloÄ3.1.0Ühexane-6-carboxylic acid derivatives represented by the formula as follows: <CHEM> Äwherein, R<1> represents a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C3-C6 cycloalkyl C1-C6 alkyl group, an aryl group, an aryl C1-C6 alkyl group, a C1-C6 alkoxy C1-C6 alkyl group, a C1-C6 hydroxyalkyl group, a C1-C6 alkylthio C1-C6 alkyl group, a C1-C6 mercaptoalkyl group, a tetrahydrofuranyl group, or a tetrahydropyranyl group; R<2> and R<3> are identical or different, and each represents a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C3-C6 cycloalkyl C1-C6 alkyl group, an aryl group, or an aryl C1-C6 alkyl group, or alternatively, R<2> and R<3> together represent -(CH2)n- (wherein n represents 2 or 3); and Y<1> and Y<2> are identical or different, and each represents a sulfur atom, an oxygen atom, or a nitrogen atomÜ. |