While your question writer enjoys a glass of wine (and an overlong trivia question), he is somewhat disturbed that a specific molecule in Sauvignon Blanc (4-methyl-4-mercaptopentan-2-one) has a strong hint of boxwood, which has an olfactory resemblance to what unpleasant smell? According to many wine enthusiasts, the odor helps to identify a high-quality Sauvignon Blanc. If wine isn't your thing, marijuana users might be more familiar with today's two-word answer as a seemingly unappealing sativa strain and phenotype of Super Silver Haze, so named because of its pungent aroma.