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

Abstract

(+)-Neomenthanethiol (1b) with (c = 1.85, CHCl₃), is prepared from (-)-menthol (2a) in three steps in 42% overall yield. ¹H- and ³¹P-NMR studies showed that the diastereomeric and optical purity of the product obtained is at least 95%. 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.