If the chromic acid oxidation is performed with stoichiometric oxidant in the presence of diethyl ether as co-solvent (a method introduced by H.C. Brown), the epimerization of l-menthone to d-isomenthone is largely avoided.
Apple cider vinegar isn't likely to be effective for weight loss. Proponents of the apple cider vinegar diet claim that drinking a small amount of apple cider vinegar before meals or taking an apple cider vinegar supplement helps curb appetite and burn fat. However, there's little scientific support for these claims.
That's not to say that apple cider vinegar is useless. Science says it does work some pretty spectacular miracles, according to Carol Johnston, PhD, a registered dietitian and professor at the School of Nutrition and Health Promotion at Arizona State University in Phoenix, who's been studying the actual effects of vinegar for years.