Notwithstanding the provisions of this or any other law, all contracts entered into after August 7, 1956, for the sale, transfer, or other disposal of housing (other than housing subject to the provisions of section
1587
(b) of this title) determined by the Secretary of Housing and Urban Development to be permanent, except contracts entered into pursuant to subsection (a) of this section, shall require that if title does not pass to the purchaser by April 1, 1957 (or within sixty days thereafter if such time is necessary to cure defects in title in accordance with the provisions of the contract), the rights of the purchaser shall terminate and thereafter the housing shall be sold under the provisions of subsection (a) of this section. For the purposes of this subsection, title shall be considered to have passed upon the execution of a conditional sales contract.