The present invention is a compound represented by the following formula (1) or a salt thereof. In the formula (1), R1 denotes a hydrogen atom, a methyl group, or a hydroxymethyl group, and n is an integer of 1 or 2.
The present invention is a compound represented by the following formula (1) or a salt thereof. In the formula (1), R
1
denotes a hydrogen atom, a methyl group, or a hydroxymethyl group, and n is an integer of 1 or 2.