Chemoselective and Odorless Transthioacetalization of Acetals Using α-Oxo-Ketene Dithioacetals as Thiol Equivalents

Abstract

Using α-oxo-ketene dithioacetals 1a as odorless thiol equivlents, an efficient and odorless transthioacetalization of acetals 2 has been developed. In the presence of MeCOCl in MeOH, the cleavage of 1a commences to generate thiols at both room and reflux temperatures, and the generated thiols then react with acetals 2 to give correspecting thioacetals 3 in good yield. This transthioacetalization is characterized by mild reaction conditions, simple procedure, good yields, and perfect chemoselectivity. It is noteworthy that only a very faint odor of thiols can be perceived during both the reaction and workup.

GRAPHICAL ABSTRACT

Keywords:

• Acetals
• chemoselectivity
• odorless thiols equivalents
• α-oxo-ketene dithioacetals
• transthioacetalization reaction

Notes

^a Conditions: 1a (1 mmol), 2 (1 mmol), MeCOCl (1.5 mmol), MeOH (2 mL).

^b Isolated yield.