B.  Ahuja, Gadakh, S., and Sudalai, A., ?Proline catalyzed sequential alpha-amination/ Prins/ Ritter amidation of aldehydes: new method of construction of tetrahydropyran units?, Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, vol. 58, no. 9, pp. 1019-1028, 2019.