Scope and limitation of the [1,4] SPh shift in the synthesis of allylic alcohols

The stereoselective synthesis of oxetanes; exploration of a new, Mitsunobu-style procedure for the cyclisation of 1,3-diols

“…In an earlier publication we had erroneously assigned these compounds as sulfoxides. 21 To resolve the ambiguity, diol 1 was oxidised to 33 and converted to 3,5-dinitrobenzoate 34 (Scheme 13). X-Ray quality crystals were grown by the liquid drop method.…”

The scope and limitation of the [1,4]-SPh shift in the synthesis of allylic alcohols†

“…4 We have previously shown that the treatment of the 4-PhS-1,3-diol 1 with toluene-p-sulfonyl chloride (TsCl) in pyridine gave instead of the expected tosylate 2, the allylic alcohol 4 in 97% yield, presumably via the sulfonium ion 3 and a [1,4]-SPh shift (Scheme 1). 5 We now report on the rearrangement of related 4-PhS-1,3-diols with TsCl in pyridine 6 with structural variation at both the migration origin and terminus and the synthesis of allylic alcohols. We comment on stereochemical effects, structural variation and the Thorpe-Ingold effect 7 on the efficiency and outcome of the reaction.…”

The scope and limitation of the [1,4]-Sbenzyl participation and debenzylation in the stereochemically controlled synthesis of substituted thiolanes

“…2. exo-Elimination to give allylic alcohols like anti-4 is favoured when PhS is the migrating group and when there is a tertiary migration origin. 1,5, 22 3. endo-Elimination to give ketones is very rare, and occurs only to a small extent when PhS is the migrating group and when there is a tertiary acyclic migration origin. 1,22 4. endo-Substitution is favoured when PhS is the migrating group and when there is a secondary migration origin.…”

“…1,5, 22 3. endo-Elimination to give ketones is very rare, and occurs only to a small extent when PhS is the migrating group and when there is a tertiary acyclic migration origin. 1,22 4. endo-Substitution is favoured when PhS is the migrating group and when there is a secondary migration origin. 1…”