(a) If a shareholder terminates his entire stock interest in a corporation--
(1) By a sale or other disposition within the requirements of section 306(b)(1)(A), or
(2) By redemption under section 302(b)(3) (through the application of section 306(b)(1)(B)), the amount received from such disposition shall be treated as an amount received in part or full payment for the stock sold or redeemed. In the case of a sale, only the stock interest need be terminated. In determining whether an entire stock interest has been terminated under section 306(b)(1)(A), all of the provisions of section 318(a) (relating to constructive ownership of stock) shall be applicable. In determining whether a shareholder has terminated his entire interest in a corporation by a redemption of his stock under section 302(b)(3), all of the provisions of section 318(a) shall be applicable unless the shareholder meets the requirements of section 302(c)(2) (relating to termination of all interest in the corporation). If the requirements of section 302(c)(2) are met, section 318(a)(1) (relating to members of a family) shall be inapplicable. Under all circumstances paragraphs (2), (3), (4), and (5) of section 318(a) shall be applicable.
(b) Section 306(a) does not apply to--
(1) Redemptions of section 306 stock pursuant to a partial or complete liquidation of a corporation to which part II (section 331 and following), subchapter C, chapter 1 of the Code applies,
(2) Exchanges of section 306 stock solely for stock in connection with a reorganization or in an exchange under section 351, 355, or section 1036 (relating to exchanges of stock for stock in the same corporation) to the extent that gain or loss is not recognized to the shareholder as the result of the exchange of the stock (see paragraph (d) of Sec. 1.306-3 relative to the receipt of other property), and
(3) A disposition or redemption, if it is established to the satisfaction of the Commissioner that the distribution, and the disposition or redemption, was not in pursuance of a plan having as one of its principal purposes the avoidance of Federal income tax. However, in the case of a prior or simultaneous disposition (or redemption) of the stock with respect to which the section 306 stock disposed of (or redeemed) was issued, it is not necessary to establish that the distribution was not in pursuance of such a plan. For example, in the absence of such a plan and of any other facts the first sentence of this subparagraph would be applicable to the case of dividends and isolated dispositions of section 306 stock by minority shareholders. Similarly, in the absence of such a plan and of any other facts, if a shareholder received a distribution of 100 shares of section 306 stock on his holdings of 100 shares of voting common stock in a corporation and sells his voting common stock before he disposes of his section 306 stock, the subsequent disposition of his section 306 stock would not ordinarily be considered a disposition one of the principal purposes of which is the avoidance of Federal income tax. [T.D. 6500, 25 FR 11607, Nov. 26, 1960, as amended by T.D. 6969, 33 FR 11998, Aug. 23, 1968]