The appropriate reg would be Treas. Reg. § 301.7701-3(g)(ii)

(ii) Association to partnership. If an eligible entity classified as an association elects under paragraph (c)(1)(i) of this section to be classified as a partnership, the following is deemed to occur: The association distributes all of its assets and liabilities to its shareholders in liquidation of the association, and immediately thereafter, the shareholders contribute all of the distributed assets and liabilities to a newly formed partnership.

https://www.law.cornell.edu/cfr/text/26/301.7701-3