Hydrolysis of Thioglycosides and Thioacetals

The mechanistic consequences of replacing an oxygen atom in an acetal by a sulfur atom are dictated by three phenomena  

Spontaneous departure of thiophenoxide from hemithioacetals of the type ArCH(OEt)SPh gives rise to a water reaction whose rate-limiting step appears to be the departure of thiophenoxide from an ion pair the ability to form such a species is reminiscent of the thiolate-carbonyl complexes detected in the mutarotation of 5-thioglucose (see Section 1.2.1.5). 

---