□喃二烯-丙二烯醚基之分子內Diels-Alder反應之研究(八)

Abstract

在□喃笫二個碳上引進二苯磷基及二苯磷氧基，並於furfurylic位置上更換不同烷基取代，以化合物4a-e、14a-e進行分子內Diels-Alder反應，以笫三丁醇鉀當作鹼，於笫三丁醇溶劑中以85℃加熱迴流，可以得到1,2-重排反應產物5a-e、15a-e，和□喃轉移反應產物16a,b，並沒有得到1,4-重排反應產物，化合物4a,b亦沒有得□喃轉移反應產物，且二苯基磷的磷容易被氧化成二苯磷氧基。 此外，當丙炔上三鍵再引進一個甲基後，在相同反應條件下則不會進行Diels-Alder反應，亦不會生成丙二烯醚基。 不同烷基取代的丙二烯醚分別與□喃及環戊二烯進行分子間Diels-Alder反應，皆無法得到環化加成反應產物，另外若以PCC氧化不同烷基取代的丙二烯醚，則可得到氧化產物40a,d,e。

We studied the intramolecular Diels-Alder reaction of the different substituent on furfurylic with diphenylphosphinyl group and diphenylphosphinoxide group was introduced on furan ring 4a-e, 14a-e , under potassium tert-butoxide as base and tert-butyl alcohol as solvent then reflux in 85℃, followed by 1,2-rearrangement of diphylphosphinyl group and diphenylphosphinoxide group 5a-e, 15a-e , and furan ring transfer products 16a,b , no 1,4-rearrangement cycloadducts were found. Also, compound 4a,b didn’t give furan ring transfer cycloadducts. And diphenylphosphinyl group are oxidated to diphenylphosphinoxide group easily. The intramolecular Diels-Alder reaction of propargyl ether, which methyl group was introduced on triple bond, with furan was not processing, and didn’t gave allenyl ether. The intermolecular Diels-Alder reactions of the different substituent on allenyl ether with furan and cyclopentadiene were not gave cycloadducts. But the different substituent allenyl ether can be oxidated by PCC to oxidation products 40a,d,e.