Patent ID: 7524951

Claim:
A compound represented by formula (1): wherein R 1 represents a hydrogen atom or a protective group of hydroxyl, R 2 represents a hydrogen atom, a protective group of carboxyl, or an anion in a carboxylate anion, wherein the anion in the carboxylate anion is in the form of a salt, Z 1 and Z 2 together represent an oxygen atom or a protective group of carbonyl, or one of Z 1 and Z 2 represents a hydrogen atom and the other represents hydroxyl or protected hydroxyl, Y represents an oxygen atom or group P(R 3 ) 3 , wherein R 3 s, which may be the same or different, represent C1-6 alkyl optionally substituted by a halogen atom, or aryl optionally substituted by a halogen atom or C1-6 alkyl in which the alkyl group may be substituted by a halogen atom.