393. Researches in the menthone series. Part XIII. The relative molecular configurations of the menthols and menthylamines

The Stereoisomerism of Cyclohexane Derivatives.

“…On the other hand, (+)-neomenthol is esterified more slowly with acetic and butyric acids than is ( -)-menthol, and the (-f-)-neomenthyl esters (acid phthalates, acetates) are correspondingly more difficult to saponify than those of ( -)-menthol (311,312,334). In comparative reaction studies of the four series of alcohols with p-nitrobenzoyl chloride, the relative rates have been found to be: menthol, 16.5; isomenthol, 12.3; neoisomenthol, 3.1; neomenthol, 1.0 (253). Sterically, the C3-hydroxyl and C4-isopropyl groups must therefore be the same: ee in menthol and isomenthol, and pp in neo-and neoisomenthol.…”

The Diastereomeric Menthyl Chlorides Obtained from (--) Menthol

“…Much menthene is formed by this latter variation. The stereochemical configuration of menthol (I) is based largely on its resistance to dehydration (8) and on the assumed generalization that the elements of water are eliminated from apex and base of adjacent carbon atoms (9). A comparable demonstration by Hückel, Tappe, and Legutke (10) that menthyl chloride has a similar stereochemical configuration (II) is based on the general tendency toward apex-base elimination of hydrogen chloride.…”

CONFORMATION OF TERPENES. II. PINOCAMPHEOLS AND PINOCARVEOLS1

“…The data quoted above constitute strong evidence in favor of the equatorial conformation for the hydroxy group in pinocampheol and isopinocampheol. The appreciably higher rate of hydrolysis of neoisopinocampheol acetate compared to that of neopinocampheol acetate parallels the relative rates of esterification of neoisomenthol and neomenthol2 (13).…”