Abstract 2??[1, 3] Dithian/dithiolan??2??ylidene??3??oxo??butanamide 2a/2b were synthesized and investigated in the thioacetalization reaction of aldehydes/ketones 3. The experiments revealed that 2a could be used as a nonthiolic, odorless 1, 3??propanedithiol equivalent in the conversion of aldehydes/ketones into the corresponding dithianes 4, however, 2b was less effective. Moreover, the chemoselectivity of the thioacetalization of 3 in the presence ...