PROTECTIVE AGENT

摘要

Disclosed is a protective agent for a hydroxyl group or a carboxyl group, which is represented by the general formula (0) below (wherein X<SUP>1</SUP> represents a hydrogen atom and X<SUP>2</SUP> represents a halogen atom, or alternatively X<SUP>1</SUP> in combination with X<SUP>2</SUP> represent a bond; R<SUP>1</SUP> and R<SUP>2</SUP> independently represent a substituted or unsubstituted alkyl or the like; A represents an oxygen atom or a sulfur atom; and R<SUP>3</SUP> represents an alkyl wherein a group having an oxygen atom and/or a sulfur atom is substituted or the like). (0)