Patent ID: 7345179

Claim:
A process for producing a compound represented by formula (IV) as described below comprising reacting a compound represented by formula (I): wherein R 11 represents a protective group of amino group, and R 2 represents hydrogen atom or a protective group of hydroxy group (with the proviso that when both R 11 and R 2 are protective groups, they are not the same protective group) with an optionally substituted arylsulfonyl chloride or an optionally substituted alkylsulfonyl chloride in the presence of a base to produce a compound represented by formula (II): wherein R 11 and R 2 are as defined above, and R 3 represents an optionally substituted arylsulfonyl group or an optionally substituted alkylsulfonyl group; reacting this compound with the compound represented by formula (III): wherein R 4 is an optionally substituted alkyl group or an optionally substituted aralkyl group, and M represents an alkaline metal atom to obtain the compound represented by formula (IV): wherein R 11 , R 2 , and R 4 are as defined above.