摘要 |
A method for producing a compound represented by the formula: wherein the ring A is a benzene ring which may be substituted in addition to the R' group; R<SUP>1 </SUP>is hydrogen or an optionally substituted hydrocarbon residue; X is a direct bond or a spacer having an atomic length or two or less between the phenylene group and the phenyl group; Y is -O-, -S(O)m- or -N(R<SUP>4</SUP>)- wherein m is an integer of 0, 1 or 2 and R<SUP>4 </SUP>is hydrogen or an optionally substituted alkyl group; R' is carboxyl, an ester thereof, an amide thereof or a group capable of forming an anion or a group convertible thereinto; n is an integer of 1 or 2; or a salt thereof, which comprises deprotecting a compound represented by the formula: wherein R is triphenylmethyl, 2-tetrahydropyranyl, methoxymethyl or ethoxy methyl, the other symbols as defined above; or a salt thereof.
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