A compound represented by the following formula: wherein R represents BR 3 R 4 wherein R 3 and R 4 are together combined with B to form a ring serving as a protecting group for B, wherein the ring is selected from the group consisting of pinacol, 2,2-dimethyl-1,3-propanediol, N-methyldiethanolamine, 1,8-diaminonaphthalene, N-methyliminodiacetic acid, 1,1,1-trishydroxymethylethane, and catechol; or R represents BX 3 - or BX 3 M wherein X represents F, and M + represents an alkali metal ion, an ammonium ion, a tetraalkylammonium ion, a tetraarylammonium ion, a tetraalkylphosphonium ion, a tetraarylphosphonium ion, or an imidazolium ion; R 1 represents hydrogen or protecting group PG 1 selected from an alkyl group having 1 to 7 carbon atoms or an aromatic group such as benzyl, p-methoxybenzyl and p-nitrobenzyl groups; R 2 represents hydrogen or protecting group PG 2 selected from benzyloxycarbonyl, acetyl, trifluoroethylcarboxy, tert-butyloxycarbonyl, fluorenylmethyloxycarbonyl, trichloroethoxycarbonyl, trifluoroacetyl, allyloxycarbonyl, benzyl, propargyloxycarbonyl, benzoyl, phthaloyl, toluenesulfonyl, and nitrobenzenesulfonyl groups; Y represents I, F, Br, NO 2, NH 2, Sn(R 6) 3, N=N-NR 78 R, OSO 2 R 9, NR 10 R 11, I + R 13, or (R 14-)I + R 13, wherein: R 6 represents alkyl group having 1 to 7 carbon atoms; R 7 and R 8, which may be the same or different, each represents hydrogen, alkyl group having 1 to 7 carbon atoms, halogen-substituted alkyl group having 1 to 7 carbon atoms, unsubstituted phenyl group, or phenyl group substituted with C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, amino or nitro groups, or else R 7 and R 8 combine with N to form a 3- to 7-membered cyclic structure; R 9 represents alkyl group having 1 to 7 carbon atoms, halogen-substituted alkyl group having 1 to 7 carbon atoms, unsubstituted phenyl group, or phenyl group substituted with C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, amino or nitro groups; and R 10 and R 11, which may be the same or different, each represents alkyl group having 1 to 7 carbon atoms, halogen-substituted alkyl group having 1 to 7 carbon atoms, unsubstituted phenyl group, or phenyl group substituted with C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, amino or nitro groups, or else R 10 and R 11 combine with N to form a 3- to 7-membered cyclic structure; R 13 represents a C 1-6 -alkyl-substituted phenyl group, a C 1-6 -alkoxy-substituted phenyl group, or a phenyl group, or a 5- to 7-membered heterocyclic group having one or more atoms of N, S or O atoms; and R 14 represents a halogen, or a tetrafluoroborate, nitrate, triflate, sulfonyloxy, toluenesulfonyloxy, or perchlorate group. R represents BR 3 R 4 wherein R 3 and R 4 are together combined with B to form a ring serving as a protecting group for B, wherein the ring is selected from the group consisting of pinacol, 2,2-dimethyl-1,3-propanediol, N-methyldiethanolamine, 1,8-diaminonaphthalene, N-methyliminodiacetic acid, 1,1,1-trishydroxymethylethane, and catechol; or R represents BX 3 - or BX 3 M wherein X represents F, and M + represents an alkali metal ion, an ammonium ion, a tetraalkylammonium ion, a tetraarylammonium ion, a tetraalkylphosphonium ion, a tetraarylphosphonium ion, or an imidazolium ion; R 1 represents hydrogen or protecting group PG 1 selected from an alkyl group having 1 to 7 carbon atoms or an aromatic group such as benzyl, p-methoxybenzyl and p-nitrobenzyl groups; R 2 represents hydrogen or protecting group PG 2 selected from benzyloxycarbonyl, acetyl, trifluoroethylcarboxy, tert-butyloxycarbonyl, fluorenylmethyloxycarbonyl, trichloroethoxycarbonyl, trifluoroacetyl, allyloxycarbonyl, benzyl, propargyloxycarbonyl, benzoyl, phthaloyl, toluenesulfonyl, and nitrobenzenesulfonyl groups; Y represents I, F, Br, NO 2, NH 2, Sn(R 6) 3, N=N-NR 78 R, OSO 2 R 9, NR 10 R 11, I + R 13, or (R 14-)I + R 13, wherein: R 6 represents alkyl group having 1 to 7 carbon atoms; R 7 and R 8, which may be the same or different, each represents hydrogen, alkyl group having 1 to 7 carbon atoms, halogen-substituted alkyl group having 1 to 7 carbon atoms, unsubstituted phenyl group, or phenyl group substituted with C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, amino or nitro groups, or else R 7 and R 8 combine with N to form a 3- to 7-membered cyclic structure; R 9 represents alkyl group having 1 to 7 carbon atoms, halogen-substituted alkyl group having 1 to 7 carbon atoms, unsubstituted phenyl group, or phenyl group substituted with C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, amino or nitro groups; and R 10 and R 11, which may be the same or different, each represents alkyl group having 1 to 7 carbon atoms, halogen-substituted alkyl group having 1 to 7 carbon atoms, unsubstituted phenyl group, or phenyl group substituted with C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, amino or nitro groups, or else R 10 and R 11 combine with N to form a 3- to 7-membered cyclic structure; R 13 represents a C 1-6 -alkyl-substituted phenyl group, a C 1-6 -alkoxy-substituted phenyl group, or a phenyl group, or a 5- to 7-membered heterocyclic group having one or more atoms of N, S or O atoms; and R 14 represents a halogen, or a tetrafluoroborate, nitrate, triflate, sulfonyloxy, toluenesulfonyloxy, or perchlorate group.