Quantitative determination of sulfur containing wine odorants at sub-ppb levels. 1. Synthesis of the deuterated analogues

[H-2(10)]-4-Sulfanyl-4-methylpentan-2-one (d(10)-SMP), [H-2(2)]-3-sulfanylh exan-1-ol (d(2)-3SH), and [H-2(5)]-3-sulfanylhexyl acetate (d(5)-3SHAc), th e -labeled analogues of impact odorants of wines and other foods, were synt hesized to be used for the quantitative determination of the natural compou nds in white and red wines by stable isotope dilution assay. The sulfidatio n was achieved by Michael addition, on mesityl oxide or ethyl hex-2-enoate, respectively, of the sulfhydryl anion generated in situ from triphenylsila nethiol and potassium fluoride under phase transfer conditions. The labelin g of 4-sulfanyl-4-methylpentan-2-one (SMP) was obtained from the commercial starting material, [H-2(6)]-acetone, so that this method could be used to synthesize C-13-labeled SMP from 13C-labeled acetone. The labeling of 3-sul fanylhexan-1-ol (3SH) and 3-sulfanylhexyl acetate (3SHAc) was obtained from reduction with lithium aluminum deuteride of the Michael adduct ethyl 5-su lfanylhexanoate and [H-2(3)]-acetylation. During the synthesis, 3SH and 3SH Ac were partially oxidized to their disulfide, which were reduced back to t he thiols by an additional reduction step; the tertiary thiol SMP was less sensitive to this oxidation..