The biogenetic-type cyclization of (+)-(3S)-2-(3-hydroxy-3-methyl-4-pentenyl)-1-methyl-3-(1-methylethenyl)cyclopentene, prepared from d-limonene, with formic acid gave stereo and regiospecifically the formates of the tricyclic compounds of the allo-cedrol skeleton, hydrolysis of which gave the unsaturated alcohols, (+)-(1S,5R,7R,8S)-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undec-2-en-8-ol (27) and (+)-(1S,5R,7R,8R-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undec-2-en-8-ol. Hydrogenation of 27 gave (+)-(1R,2S,5R,7R,8S)-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undecan-8-ol, (+)-2-epi-allo-cedrol.
用
甲酸水解可得到烯丙基
柏木醇骨架的
三环化合物的立体和特定的
甲酸酯,
水解后可得到不饱和醇,即 (+)-(1S,5R,7R,8S)-2,6,6,7-四甲基
三环[5.2.2.01,5]undec-2-en-8-ol (27) and (+)-(1S,5R,7R,8R-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undec-2-en-8-ol.27 的氢化反应得到了 (+)-(1R,2S,5R,7R,8S)-2,6,6,7-四甲基
三环[5.2.2.01,5]十一碳-8-醇、(+)-2-表烯-8-醇。