- Danishefsky’s diene
.
Its first reported synthesis was by reaction of
trimethylsilyl chloride with "4-methoxy-3-buten-2-one" andzinc chloride [Preparation and Diels-Alder Reaction of a Highly Nuclerophilic Diene. Org. Synth., Coll. Vol. 7, p.312 (1990); Vol. 61, p.147 (1983). [http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv7p0312 Link] ] :Its reaction with
maleic anhydride is a fast one.In a reaction with an alkene the
silyl ether is asynthon for acarbonyl group through anenol while theether group is susceptible to anelimination reaction and capable of forming a newalkene group. In addition highregioselectivity is obtained with unsymmetrical alkenes with a preference for an 1,2-relation of the ether group with the electron-deficient alkene-carbon. All this is exemplified in thisAza Diels-Alder reaction ["Asymmetric aza-Diels-Alder reaction of Danishefsky's diene with imines in a chiral reaction medium" Pegot B, Nguyen Van Buu O, Gori D, Vo-Thanh GBeilstein Journal of Organic Chemistry , 2006 [http://bjoc.beilstein-journals.org/content/pdf/1860-5397-2-18.pdf Link] ] [This is anasymmetric reaction with a chiralionic liquid aschiral solvent . The reportedchemical yield is 66% with 60%diastereomeric excess ] :References
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