Menthyl acetate

Menthol (hRf 15) and menthyl acetate hRt 55) yielded blue chromatogram zones caryophyllene hRf 90) and caryophyllene epoxide hRf 20 — 25) appeared red-violet and thymol hRf 40 — 45) appeared brick red in color. 

Fig. 1 Schematic sketch (A) of the separation of essential oil components (ca. 500 ng of each component) and reflectance scan of the mixture (B). Menthol (1), caryophyllene epoxide (2), thymol (3), menthyl acetate (4), caryophyllene (5), mixture (G).

Menthol forms an acetate, menthyl acetate,. COCHj, a thick... 

Menthyl Acetate.—This ester, of the formula CHg. CO. OC, H g, is-present in oil of peppermint, its odour being an important characteristic of that oil. It can be prepared by heating menthol with acetic anhydride and sodium acetate. Its characters are as follows —... 

Geranjl, linalyl, and bornyl acetates Menthyl acetate (for peppermint oil) Geranyl tiglate (for roee-geranium oil) Santalyl acetate (for sandalwood oil) Sabinyl acetate (for savin oil). ... 

In these estimations it -is necessary to calculate all the esters and all the alcohols to one formula, expressing the result, for instance, as menthyl acetate, although as a matter of fact small quantities of the corresponding propionate and butyrate may also be present, which it is impossible to estimate separately. 

A report of an unusually high stereoselectivity (93% ee) in the addition of menthyl acetate to acetophenone was later corrected by Solladie et al. The real ee is only 58% see S. Mitsui, K. Konno, 1. Onuma, K. Shimizu, Nippon Kagaku Zasshi 85, 437 (1964) Chem. Ahstr. 61. 13167 f. (1964). 

In some cases, especially wdth cyclic compounds, the more stable alkene forms and Zaitsev s rule applies. For example, menthyl acetate gives 35% of... 

Figure 11.6 indicates approximate /-values for some of the components in peppermint oil on a BPX-5 column this column selects mainly on the basis of molecular weight and shape. For example p-pinene has the same molecular weight as limonene but has a more compact shape and thus a lower /-value. Menthyl acetate has a higher /-value than menthol because of its higher molecular weight. 

Asymmetric hydrolysis of ( )-menthyl acetate by Rhodotorula mucilaginosa is reported. ... 

Menthol from Dementholized Cornmint Oil. Dementholized cornmint oil, from which (-)-menthol has been removed by crystallization and which still contains 40-50% free menthol, can be reused for producing (-)-menthol. The fairly large quantity of (-)-menthone in the oil (30-50%) is hydrogenated to form a mixture of mainly (-)-menthol and (+)-neomenthol the (-)-menthyl esters present (chiefly (-)-menthyl acetate) are saponified. Additional (—)-menthol is then separated from other components by crystallization, distillation, or via the boric acid esters. 

Menthyl acetate is prepared by acetylation of (-)-menthol (e.g., with acetic anhydride). It is used mainly in peppermint flavors and reconstituted peppermint oils, but also to a small extent in perfumery. 

Occurs in essential oils. It is synthesized by esterification of racemic menthol. Its odor is crisper and less fruity than that of (—)-menthyl acetate. It is used for essential oil compositions and occasionally in household perfumery. 

Mentha piperita and Mentha canadensis Menthyl acetate Menthol [94]... 

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