Use of menthyl 2-methoxynaphthalene-1-sulfinates in the Andersen synthesis of optically active sulfoxides. Facile cleavage by Grignard reagents of some aromatic methyl ethers

Article abstract of DOI:10.1071/CH9941925

The pure crystalline diastereomers (1R,2S,5R)-menthyl (R)- and (S)-2-methoxynaphthalene-1-sulfinate have been prepared and, by reaction with Grignard reagents (the Andersen procedure), converted into optically active alkyl and aryl 2-methoxynaphthyl sulfoxides in 67-77% yields. Use of an excess of Grignard reagent results in facile 0-alkyl cleavage of the methoxy group to the corresponding naphthol or a competing loss of the alkylor aryl-sulfinyl group to from 2-methoxynaphthalene. Pure diastereomers of menthyl 2,7-dimethoxynaphthalene-1-sulfinate and menthyl 4-methoxynaphthalene-1-sulfinate have also been prepared and their reactions with Grignard reagents have been studied.