After a plan of complete liquidation has been adopted, Purple Corporation sells its only asset, land, to Rex (an unrelated party) for $500,000. Under the terms of the sale, Purple receives cash of $100,000 and Rex's note in the amount of $400,000. The note is payable over five years ($80,000 per year) and carries an appropriate rate of interest. Immediately after the sale, Purple distributes the cash and note to Helen, the sole shareholder of Purple Corporation. Helen has a basis of $50,000 in the Purple stock. What are the tax results to Helen if she wants to defer as much gain as possible on the transaction? Assume that the installment note possesses a value equal to its face amount.