抄録
Alkylation of methyl=methylthiomethyl=sulfoxide (formaldehyde dimethyl mercaptal S-oxide : FAMSO [1]) with alkyl halides was carried out effectively in tetrahydrofuran (THF) with sodium naphthalene as condensing agent. From n-hexyl bromide, heptylaldehyde dimethyl mercaptal S-oxide [2a] was obtained in 70% yield as main product, and from benzyl bromide, phenyl acetaldehyde dimethyl mercaptal S-oxide [2b] was obtained in 82% yield. Several by-products separated were identified to be methyl hexyl sulfoxide [5], n-dodecane [6], methyl-1-heptenyl sulfoxide ([3a], [3b]), methyl benzyl sulfoxide [8], dibenzyl [9], methyl styryl sulfoxide ([3c], [3d]).
When the aldehyde dimethyl mercaptal S-oxide [2] was distilled under reduced pressure at 160°C, methyl vinyl sulfide [3] was obtained in quantitative yield. From compound [2a], methyl-1-heptenyl sulfide ([3a], [3b]) was obtained in 97% yield, and from compound [2b], methyl styryl sulfide ([3c], [3d]) was obtained in 96% yield. The by-products in the pyrolysis of compound [2a] were identified to be n-heptylaldehyde [4], S-methyl heptane thioate [12], α-methylthio heptylaldehyde [13], H2O [10], dimethyl disulfide [11].
