Natural (-)-menthol, the essential oil primarily responsible for the flavor and aroma of peppermint, is the 1R,2S,5R -stereoisomer. (a) Identify (-)-menthol from the structures you drew for Problem 50, part (b). (b) Another of the naturally occurring diastereomers of menthol is ( + )-isomenthol, the 15,2/?,5/?-stereoisomer. Identify (+)-isomenthol among your structures, (c) A third is (+)-neomenthol, the lS,25,5R-compound. Find (+)-neomenthol among your structures, (d) Based on your understanding of the conformations of substituted cyclohexanes (Section 4-4), what is the stability order (from most stable to least) for the three diastereomers. menthol, isomenthol, and neomenthol?