If a business purchases large assets (generally over $200, or over $2500 if you make the De Minimis election) that are used for more than one year for that business, the cost is generally depreciated over many years.  In the case of renting out Residential Real Estate, that cost is spread out over 27.5 years.

So no, you can't claim the full amount as a deduction.  A FULL YEAR of using it for business would only get a depreciation deduction of 1/27.5th of the cost (not including the value of any land, and a partial year of using it for business would be prorated).