Synthesis and Stereochemistry of 3,5-Bis(carbomethoxy)-2,6-diphenyltetrahydro-4H-thiopyran-4-ones and Derivatives

Article abstract of DOI:10.1021/jo00326a030

3,5-Bis(carbomethoxy)-2,6-diphenyl-4H-thiopyran-4-one (2) and its 5,6-trans-dihydro derivative 14 were synthesized by dehydrogenation with active manganese dioxide in refluxing chloroform of the corresponding diastereoisomeric mixture of cis- and trans-2,6-diphenyltetrahydro compounds 5 and 6.The latter were prepared by the addition of hydrogen sulfide to dimethyl dibenzalacetonedicarboxylate (4).The stereochemistry and the reaction with N-chlorosuccinimide (NCS) of the diastereoisomers 5 and 6 and their corresponding sulfoxides 11 and 8 are elucidated.NCS reacted at the active methylene position in preference to the sulfide or sulfoxide function.