2- Isopropyl-5-methylcyclohexanol

Isopropyl-5-methylcyclohexanol, m 12 Isovaleraldehyde, ml81 5-Keto-l,7,7-trimethylnorcamphane, c3... 

The initial lactone 21 was diastereoselectively opened with an excess of LiNu nucleophiles, namely lithio(S)-l-phenylethanamine (Fig. 6b the diastereomeric ratio of 22 was 3 1) and lithio(l/ ,25,51 )-2-isopropyl-5-methylcyclohexanol (Fig. 6c the diastereomeric ratio of 22 was 3 2). The acidification (with 2 N HC1) of the mixture of diastereomeric lithium salts 22 thus obtained led directly to the... 

Fig. 6 (a) A cycle proposed for a molecular motor based on the opening of an achiral lactone 21 with a chiral nucleophile LiNu compound 22 is a mixture of diastereomers (same should hold for 23 and 25) of which only one diastereomer is shown here, 23 is the same as 25, and 26 is the same as 24 (b) structural formula of lithio(S)-l-phenylethanamine (a LiNu nucleophile) (c) structural formula of lithio(lf ,2S,5/f)-2-isopropyl-5-methylcyclohexanol (a LiNu nucleophile)... 

SYNS CYCLOHEXANOL, 2-ISOPROPYL-5-METHYL- FEMA No. 2665 HEXAHYDROTHYMOL 2-ISOPROPYL-5-METHYLCYCLOHEXANOL P-MENTHAN-3-OL 1-iMENTHOL 5-METHYL-2-(l-METHYLETHYL)CY-CLOHEXANOL PEPPERMINT CAMPHOR TRA-KILL TRACHEAL MITE KILLER... 

Hexahydrothymol 2-isopropyl-5-methylcyclohexanol 4-iso-propyl-l-methylcyclohexan-3-ol 3-p-menthanol p-menthan-3-ol dZ-menthol peppermint camphor racemic menthol. 

Two years later, Marko et al. reported an improved catalytic system which only required 0.25 equivalent of potassium carbonate instead of 2 equivalents (89). The oxidation reaction described above is dramatically influenced by the nature of the solvent. Thus, if the reaction was performed in fluorobenzene, total conversion of undecan-2-ol to undecan-2-one could be reached with 0.25 equivalent K2CO3, whereas 2 equivalents of base were necessary in toluene to convert 90% of this secondary aliphatic alcohol (Table VI). These optimized conditions were applied to a variety of functionalized alcohols and the results are reported in Table VII. The catalyst tolerates both sulphur and nitrogen substituents on the substrate. Indeed, (thiophen-2-yl)methanol, N-protected (S)-valinol or (S)-prolinol could be oxidized to the corresponding aldehydes with very good yields. In addition, no racemization was detected for the two P-amino alcohols as well as for (2S,5i )-2-isopropyl-5-methylcyclohexanol. The hindered endo- and exo-borneol are both converted to camphor with similar reaction rates, despite their distinctly different steric properties. 

In Problem 4.30 you were asked to draw the preferred conformation of menthol on the basis of the information that menthol is the most stable stereoisomer of 2-isopropyl-5-methylcyclohexanol. We can now completely describe (—)-menthol structurally by noting that it has the R configuration at the hydroxyl-substituted carbon. 

There are four cis-trans isomers of 2-isopropyl-5-methylcyclohexanol (See Examples 3.10, 3.11)... 

Scheme 9.7. The oxidation of (+)-[15, 2f ,5.S ]-2-isopropyl-5-methylcyclohexanol [(+)-menthol] to the corresponding ketone (+)-[2i ,5.S ]-2-isopropyl-5-methylcyclohexanone [(+)-menthone] with cold aqneons permanganate (Mn04 ) solution and its cleavage to many fragments by warm aqueous permanganate (Mn04 ). A potential pathway accounting for the initially formed fragmentation product is also shown.

The lUPAC name for menthol is 2-isopropyl-5-methylcyclohexanol (Section 2.4)... 

All operations were performed aecording to the standard Schlenk teehniques. Starting materials were of commercial origin, with the exception of S-2-bromoacetoxypropionic acid ethyl ester, the bromoacetate of D-menthol [(IS, 2R, 5S)-2-isopropyl-5-methylcyclohexanol] and L-menthol [(IR, 2S, 5R)-2-isopropyl-5-methylcyclo-hexanol] as well as of dicobalt octacarbonyl, which were prepared aeeording to published procedures. 

Menthol is the most stable stereoisomer of 2-isopropyl-5-methylcyclohexanol and has the R configuration at the hydroxyl-substituted carbon. 

Menthol (1, (l/ ,3/ ,45-l-methyl-3-hydroxy-4-isopropyl-cyclohexane lUPAC name (l/ ,25,5/ )-2-isopropyl-5-methylcyclohexanol), is a natural compound, a fragrant teipenoid present in peppermint and other mint oils. 

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