Synthesis of (+)-Neomenthanethiol and Some of Its Derivatives. A New Example of Asymmetric Induction in the Sulfoxide Synthesis

Article abstract of DOI:10.1055/s-1987-28150

(+)-Neomenthanethiol (1b) with <α>_D²⁰+53.9 deg (c=1.85, CHCl3), is prepared from (-)-menthol (2a) in three steps in 42percent overall yield. 1H- and 31P-NMR studies showed that the diastereomeric and optical purity of the product obtained is at least 95percent.Methylation of (+)-1b leads to (+)-methyl neomenthyl sulfide (11) which undergoes oxidation to the corresponding sulfoxide (+)-13 (a mixture of diastereomers in a 69:31 ratio) and sulfone (+)-12.