中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 4-hydroxymethyl-3-methyl-2-cyclohexen-1-one | 58403-93-3 | C8H12O2 | 140.182 |
A cycloaddition approach to the functionalized tricyclo[9.3.1.03,8]pentadecene skeleton contained in Taxol® is described. The cyclohexenone 13 was converted as illustrated to the nitrile-aldehyde 24 to which the diene and acetylenic side chains were attached by sequential nucleophilic additions. Removal of the trimethylsilyl protecting group and Dess–Martin oxidation afforded the triene 35. Microwave-assisted thermal cyclization stereoselectively generated the tricyclic ketone 36 whose structure was further established by conversion to the aromatic system 37 upon treatment with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). An epoxidation sequence was developed to introduce the epimeric C13 alcohol 47 as required for this cycloaddition strategy. Alternatively, an allylic oxidation (CrO3, 3,5-dimethylpyrazole) afforded the C13 ketone 49. Keywords: Taxol®, Diels–Alder, synthesis, diterpene, alkaloid.