AN ENANTIOSELECTIVE CENTRAL AXIAL CENTRAL CHIRAL ELEMENT TRANSFER PROCESS LEADING TO A CONCISE SYNTHESIS OF (+)-STERPURENE - INTRAMOLECULAR DIELS-ALDER REACTIONS OF VINYLALLENE SULFOXIDES
AN ENANTIOSELECTIVE CENTRAL AXIAL CENTRAL CHIRAL ELEMENT TRANSFER PROCESS LEADING TO A CONCISE SYNTHESIS OF (+)-STERPURENE - INTRAMOLECULAR DIELS-ALDER REACTIONS OF VINYLALLENE SULFOXIDES
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DOI：
10.1021/ja00192a033
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发表时间：
1989-05-10
影响因子：
15
通讯作者：
OKAMURA, WH
中科院分区：
文献类型：
--
作者：
GIBBS, RA;BARTELS, K;OKAMURA, WH
The intramolecular Diels-Alder (IMDA) reaction of vinylallene sulfoxide 19 as the diene component occurs in a rapid and stereoselective manner at room temperature to give tricyclic 20 in good yield. Sulfoxide 19 cyclizes .apprx. 140 times faster than the corresponding hydrocarbon 15a. It was also shown that gem-dimethyl substitution on the tether linking the vinylallene and vinyl group accelerates the rate of cyclization by only a factor of .apprx. 2.6. Treatment of enantiomerically enriched diene propargyl alcohol 6 with benzenesulfenyl chloride gave vinylallene sulfoxide 4 which cyclized in a highly enatio- and diastereoselective fashion to afford optically active tricyclic sulfoxide 5. Sulfoxide 5 was converted in two steps to the novel sesquiterpene fungal metabolite (+)-sterpurene, thus establishing its absolute configuration. By use of 2D NMR techniques, most of the proton and carbon signals in the 1H and 13C NMR spectra of sterpurene (8) and the precursor diene 33 were assigned.
