BIOLOGICALLY ORIENTED ORGANIC SULFUR CHEMISTRY .I. REACTIONS OF THIOLS WITH HIGHLY REACTIVE CARBONYL COMPOUNDS

Approximate equilibrium constants (K) were obtained for the uncatalyzed reaction of 1-propanethiol with various carbonyl compounds in methylene chloride solution, leading to the formation of α-hydroxy sulfides. Many of the carbonyl compounds were of a highly reactive type, typified by a propensity to form isolable hydrates. The values of K obtained ranged from nearly 0 to in excess of 104. In instances where values of K were equal to or greater than about 102, the α-hydroxy sulfides formed could not be converted in the presence of acid catalyst and excess thiol into mercaptals or mercaptoles. However, where K values were in the range of about 0-102, the well-established conversion into mercaptals or mercaptoles could be achieved readily in the presence of hydrogen chloride or boron trifluoride. Values of K with chloral and tertiary thiols were similar to those with 1-propanethiol. 1-Dodecanethiol was much more sluggish in its reaction with chloral than were short-chain primary or tertiary thiols. © 1969, American Chemical Society. All rights reserved.