Condensates 4-6 undergo reductive dimerization with Sm in THF containing aqueous NH4Cl to produce 7-9, whereas with Zn under similar reaction condition 3-5 produce 10-12.
Ghosh, Chandra Kanta; Sahana, Sirin; Bandyopadhyay, Chandrakanta, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1993, vol. 32, # 6, p. 624 - 629