| Research Abstract |
In order to develop our intramolecular double Michael reaction, which proceeds effectively and high selectively, and apply to natural product synthesis, we examined a development of new reactions which afford four-membered compounds through an intramolecuar randem Michael reaction and also an asymmetric synthesis under the presence of chiral auxiliary or chiral reagent. Moreover, we tried total synthesis of polycylic natural product by new reaction.
In studies on intramolecuar double Michael reaction, tricyclo[4.3.0.0^<3,7>]decane, tricyclo[6.3.0.0^<3,9>]undecane and tricyclo[5.2.1.0^<1,5>]decane systems have been constructed under high and stereoselective manner by reaction of cyclopentenone or cyclohexenone derivatives with alpha, beta-unsaturated esters, and then the last compounds have been transformed into a sesquiterpene, cedranediol.
The highest optical parity was 59% in asymmetric double Michael reaction and it is further necessary to investigate reaction condition in this transformation. Synthesis of antitumor diterpene, taxol, has been examined by our reactions, and BC ring system of this compound was obtained by an intermolecualr aldol reaction and AB ring by tandem radical cyclization. This study provids poweful methods for a synthese of taxol.
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