Dieb alder reaction

The Dieb-Alder reaction is a purely cia addition the relative positions of the substituents are retained in the adduct (compare anthracene and maleic anhydride above). ... 

The first step is an intramolecular Dieb-Alder reaction. The regioselectivity of this transformation may he explained as follows The reaction can yield annelated products of type 34 by cyclization in a quasi, ortho sense or bridged products of type 36 by cyiization in a... 

I 2 The Diene-Transmissive Hetero-Dieb-Alder Reaction... 

Dieb-Alder catalyst. The key step in a recent total synthesis of androstanes is a SnCVcatalyzed Diels-Alder reaction of 1 with the (Z)-dienophile 2. The geometry of the diene favors addition ami to the C,0-methyl group, and the catalyst promotes the desired enrfo-orientation. A1C1, and BF3 ctherate are less suitable for additions involving aliphatic bifunctional dienophiles. The initial adduct a can be isolated, but in only 15-20% yield. The synthesis of the androstane 4 is completed by ketalizatioh of 3 followed by a novel cyclization affected with dimsylsodium. ... 

Dieb-Alder catalyst. The complex (1) catalyzes the homo-Diels-Alder condensation of vinyl compounds to norbomadicne. Thus the reaction of acrylonitrile with norbornadiene in the presence of this complex gives 8-cyanotetracyclo[4.3.0.0. 0 -nonane (2) as a mixture of epimers in 93 % yield. The yield of (2) using bis(triphenyl-phosphine)dicarbonylnickel(O) as catalyst is 86%. 

Dieb-AUer reaetums. N-Acyl-l-amino-l,3-dienes such as (1) are useful dienes for Diels-Alder reactions, as formulated in equation (I). They are more active than N-trichloroacetyl-l-amino-l,3-dienes. ... 

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