No abstract

The synthesis of a single diastereomer of 3‐acetoxy‐2‐(trifluoromethyl)‐4‐hydroxy‐3,4‐dihydro‐2H‐thiopyran from the mixture of diastereomeric cycloadducts of p‐tolyl trifluorodithioacetate and 1‐acetoxybutadiene is described. Its acetylation and nucleophilic chlorination provides glycosylating agents with different leaving groups have been prepared. Their reactions with various O‐, S‐, N‐ and C‐nucleophiles have been studied. Depending on the conditions of the experiments, the reactions proceed as Ferrier (I) reactions affording 3‐acetoxy‐2‐(trifluoromethyl)‐6‐substituted‐3,6‐dihydro‐2H‐thiopyrans or as formal direct replacement of the leaving group in the position 4 giving 3‐acetoxy‐2‐(trifluoromethyl)‐4‐substituted‐3,4‐dihydro‐2H‐thiopyrans. The stereochemistry of the resulting products and all their precursors is discussed.