TY - JOUR AU - Zard, Samir Z. TI - Sulfur Betaines from S-Propargyl Xanthates. Unusual Chemistry from a Simple Functional Group SN - 0039-7881 SN - 1437-210X PY - 2019 JO - Synthesis JF - Synthesis LA - EN VL - 51 IS - 05 SP - 1006 EP - 1020 ET - 2019/01/08 DA - 2019/02/15 KW - S-propargyl xanthates KW - sigmatropic rearrangement KW - betaines KW - esters KW - inversion KW - cycloaddition AB - S-Propargyl xanthates undergo upon heating a [3,3] sigmatropic rearrangement followed by a reversible ring closure into a novel betaine. This betaine can be implicated in carbon–carbon bond forming processes, in the synthesis of esters, in the inversion of secondary alcohols, in the formation of alkenes, for the generation of rigid, cisoid dienes that are highly reactive in both inter- and intra-molecular Diels–Alder cycloadditions, and in various other synthetically useful transformations.1 Introduction2 An Unexpected Transformation3 Evidence for the Betaine Intermediate4 A Method for the Synthesis of Esters and for the Inversion of Secondary Alcohols5 A General Alkylation Process6 The Case of Carbon Acids7 A Synthesis of Alkenes8 Further Trapping Experiments. Concerted or Not Concerted?9 Rigid Cisoid Dienes10 Propargyl Radicals11 Concluding Remarks PB - Georg Thieme Verlag DO - 10.1055/s-0037-1611638 UR - http://www.thieme-connect.de/products/ejournals/abstract/10.1055/s-0037-1611638 ER -