9-Hydroxy-l,8-cineole

Miyazawa, M., Y. Noma, K. Yamamoto, and H. Kameoka, 1991e. Biotransformation of 1,4-cineole to 2-endo hydroxy-l,4-cineole by Aspergillus niger. Ghent. Express, 6 A. 

Miyazawa, M., K. Yokote, and H. Kameoka, 1995c. Biotransformation of 2-e rfo-hydroxy-l,4-cineole by plant pathogenic microorganism, Glomerella cingulata. Proceedings of the 39th TEAC, pp. 352-353. 

Cineole, 13, is a natural herbicide [73]. Its hydroxy derivative 14 (2-hydroxy-1,4-cineole 1,4-epoxy-p-menthane-2-ol) is a constituent of oil from rhizomes of Ferula jaeschkeana [74]. Its 2-methylbenzyl ether 15 (cinmethylin) is a preemergence grass herbicide [75, 76]. Alcohol 14 can be prepared by microbial hydroxy-lation of 13 [77]. This also produces ketone 16 and its enantiomer [78]. The fragrance of ketone 16 and isomeric l-isopropyl-4-methyl- 7-oxabicyclo[2.2.1] heptan-2-one is very similar to that of 14 and menthone [79]. Mullilam diol 17, a dihydroxy derivative of 13, has been isolated from Zanthoxylum rhetsa, a plant that exhibits antibiotic activity which is prescribed in dyspepsia and diarrhea. The eight-carbon system rengyoxide has been found in Forsythia suspensa fruits [80] (Fig. 4). 

Figure 4.1. (Continued) (11) Ho-diendiol I (3,7-dimethyl-l,5-octadiene-3,7-diol) (12) endiol (3,7-dimethyl-l-octene-3,7-diol) (13) Ho-diendiol II (3,7-dimethyl-l,7-octadiene-3,6-diol) (14) citronellol (3,7-dimethyl-6-octen-l-ol) (15) nerol (Z), geraniol (E) (3,7-dimethyl-2,6-octadien-l-ol) (16) neroloxide (17) 2-exo-hydroxy-l,8-cineol (18) 1,8 -cineol (19) wine lactone (20) cis- and /ram-1,8-terpin (21) p-menthenediol I (p-menth-l-ene-7,8-diol) (22) ( )-geranic acid (3,7-dimethyl-2,6-octadienoic acid) (23) (/. )-2,6-dimethyl-6-hydroxyocta-2,7-dicnoic acid (24) (E- and Z)-sobrerol or p-menthenediol II (/>menth-l-ene-6,8-diol) (25) cis- and trans-rose oxide (26) triol (2,6-methyl-7-octene-2,3,6-triol) (27) hotrienol [(5 )-3,7-dimethylocta-l,5,7-trien-3-ol] (28) myrcenol (2-methyl-6-methylene-7-octen-2-ol).

Figure 4.8. The GC/MS-EI (70eV) SCAN mode chromatogram of compounds formed by acid hydrolysis of a Raboso grape skins extract. Peak 1. frans-furanlinalool oxide peak 2. cfs-furanlinalool oxide I.S.l, internal standard (1-octanol) peak 3. (Z)-ocimenol peak 4. ( )-ocimenol peak 5. a-terpineol I.S.2, internal standard (1-decanol) peak 6. 2-exo-hydroxy-l,8-cineol peak 7. benzyl alcohol peak 8. P-phenylethanol peak 9. actinidols A peak 10. actinidols B peak 11. endiol peak 12. eugenol peak 13. vinylguaiacol peak 14. p-menthenediol I peak 15. 3-hydroxy-P-damascone peak 16. vanillin peak 17. methyl vanillate peak 18. 3-oxo-a-ionol peak 19. 3-hydroxy-7,8-dihydro-P-ionol peak 20. homovanillic alcohol peak 21. vomifoliol.

A number of pyrans, including 3-hydroxy-tetrahydropyran (both axial conformer, 29 and equatorial conformer, 30), 2-methoxy-tetrahydropyran 33, 3-methyl-tetrahydropyran 32, and several 4-substituted tetrahydropyrans, along with 2-methyl-l,3-dioxolane and the rigid cyclic ethers 7-oxabicyclo[2.2.1]heptane and 1,8-cineole, were studied extensively by NMR. These empirical results, in conjunction with the literature data for a variety of acyclic and cyclic ethers, were used to examine the reliability of O-substituent chemical shift models in these systems. The empirical data correlate well with predictions made from the model and it is concluded that ethereal oxygen substituent chemical shifts are due to both steric and electrostatic terms <1998J(P2)1751>. 

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