P-Acoradiene

P-acoradiene [295]. These compounds were seen in all other trees but apparently at significantly different quantitative levels. For structures 286-298 see Fig. 3.13. 

Since the deoxygenation involved in the conversion of 134 to 136 and 137 occurs with complete isomerisation of the double bond, this meant that the correlation target now had to be P-acoradiene. The successful sequence undertaken is as shown in Scheme 32. In the event, the... 

Tomita and Hirose have reported that the reaction of P-acoradiene (226) with formic acid affords, after saponification, the newly discovered natural sesquiterpene allocedrol (227-OH) (297, 298), along with several other products. The structure of allocedrol is enantiomeric to that obtained by hydration of the carbonium ion intermediate (220) depicted in the zizaene biogenesis. This cyclization is presumably less efficient than the a-acoradiene- cedrene cyclization (213- 214) since ring... 

However, the composition of the volatile oil obtained from the herb also differs markedly from that of the seeds. Eleven components out of 21 are similar in both herb and seed oils, while some differences have been observed between the relative amounts of /J-pinene, a-terpinene, p-cymene, a-terpineol, perilla aldehyde, thymol, a-cis-bergamotene, acoradiene and... 

Application of microelements spray increased the main constituents, such as cumin aldehyde, p-cymene, a-terpineol, thymol and acoradiene. On the other hand, spraying the cumin plant with microelements decreased other constituents, especially /Tpinene. No marked differences between the relative percentages of the minor constituents of cumin herb oil, due to application of trace element treatments, were observed. However, for seed oil, an increase in cumin aldehyde, acoradiene and... 

Further studies cf. Vol. 6, p. 61) on the formic acid-catalysed conversion of carotol (101) into daucene (102) and acoradienes (103) have shown that prolonged exposure to 90% HCO2H results in the disappearance of (102) and (103) and the formation of a mixture of at least five compounds. Two of these compounds have been identified... 

Prezizaene (119) and the related tricyclic sesquiterpenoids (120)—(122) have been isolated from Eremophila georgii. The absolute stereochemistry of these compounds is antipodal to that of the zizaene sesquiterpenoids found in vetiver oil cf. Vol. 3, p. 123 Vol. 4, pp. 94—96) and their biosynthesis probably involves cyclization of 8-acoradiene (115) and rearrangement of the intermediate allocedryl (116) or cedryl (117) carbonium ions or their biological equivalents cf. Scheme 14). ... 

Riccardia miyakeana Acoradiene a-Copaene P-Copaene Cuparene p-Elemene... 

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