Tetrahydropyridines from 3-Picoline 1-Oxide and tert-Butyl and 1-Adamantyl Mercaptans in Acetic Anhydride. Structural Elucidation by Long-Range 2D J(C-H) Resolved NMR Spectroscopy

Article abstract of DOI:10.1021/jo00207a018

The reaction of 3-picoline 1-oxide with either tert-butyl or 1-adamantyl mercaptan in acetic anhydride yielded a mixture of 2-(alkylthio)-3-picolines, 2- and 3-(alkylthio)-5-picolines, and trans,trans-1-acetyl-2-(alkylthio)-3,4-diacetoxy-1,2,3,4-tetrahydropyridines 5.When triethylamine was included in such reactions, the same picolyl sulfides (albeit in different yields) were obtained together with 1-acetyl-2-(alkylthio)-3-hydroxy-3-methyl-4-acetoxy-1,2,4,4-tetrahydropyridines 6.The structure of 6d was determined from an analysis of the long-range proton-carbon-13 spin coupling constants obtained from heteronuclear 2D J resolved experiments.The sulfide and alcohol of 6d were found to be trans and the alcohol and acetoxy group cis.