Diphenylmethane protective agent

A diphenylmethane compound represented by general formula (1):

• wherein:
• Y represents —OR19 (wherein R19 represents a hydrogen atom or an active ester-type protecting group), —NHR20 (wherein R20 represents a hydrogen atom, a C1-6 linear or branched alkyl group, or an aralkyl group), an azide, a halogen atom, an oxime combined with a methylene group, or a carbonyl group combined with a methylene group,
• at least one of R1 to R10 represents a group represented by formula (2):
• —O—R11—X-A (2)
• and the others of R1 to R10 each independently represent a hydrogen atom, a halogen atom, a C1-4 alkyl group, or a C1-4 alkoxy group;
• R11 represents a C1-16 linear or branched alkylene group;
• X represents O or CONR21 (wherein R21 represents a hydrogen atom or a C1-4 alkyl group);
• and A represents a group represented by formula (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), or (13):
• wherein R12, R13, and R14 may be the same or different and each independently represent a C1-6 linear or branched alkyl group or an optionally substituted aryl group;
• R15 represents a single bond or a C1-3 linear or branched alkylene group;
• and R16, R17, and R18 each independently represent a C1-3 linear or branched alkylene group.