Method for producing purified formylcyclopropane compound and intermediate of such formylcyclopropane compound

An alkali metal hydroxymethanesulfonate represented by the formula (2):

• wherein R1 represents an alkyl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group;
• an aryl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group;
• a heteroaryl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group;
• or an aralkyl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group, and M represents an alkali metal.

A method for producing an alkali metal hydroxymethanesulfonate represented by the formula (2):

• wherein R1 represents an alkyl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group;
• an aryl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group;
• a heteroaryl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group;
• or an aralkyl group which may be substituted with at least one selected from a group consisting of a halogen atom, a C1-C3 alkoxy group and a C6-C10 aryloxy group, and M represents an alkali metal, comprising reacting a formylcyclopropane compound represented by the formula (1):
• wherein R1 represents the same meaning as defined above, with an alkali metal hydrogen sulfite.