Aldehydes, as dienophiles

The Asymmetric Diels-AIder Reaction of a,jS-Unsaturated Aldehydes as Dienophiles 1.2.1.1 Aluminum... 

The Asymmetric Diels-Alder Reaction of a,/ -Unsaturated Aldehydes as Dienophiles 6... 

Chiral Aldehydes as Dienophiles Synthesis of Long-Chain Sugars... 

HETERO DIELS-ALDER ADDITIONS 13.6.1 Achiral Aldehydes as Dienophiles... 

An important development in the hetero Diels-Alder reaction came when Jurczak used high pressure to help improve the reactivity of dienes with aldehydes. 1-Methoxybutadiene, for example, was shown to react at 15-25 kbar (I bar = l(X) kPa) with a variety of unactivated aldehydes. - These reactions give predominantly endo adducts and allow for the use of simple alkyl and aromatic aldehydes as dienophiles. Jurczak also realized the importance of this reaction in the synthesis of carbohydrates and applied it to the construction of simple monosaccharide derivatives (see Section 2.5.2. ). " ... 

Catalysis of Diels-Alder Reactions. EtAlCb is a useful Lewis acid catalyst for Diels-Alder reactions. It is reported to be more efficacious for the Diels-Alder reaction of Acrolein and butadiene than either AICI3 or Et2AlCl. It is a useful catalyst for intramolecular Diels-Alder reactions with a,p-unsaturated esters (eq 4) and aldehydes as dienophiles. It has also proven to be a very efficient catalyst for the inter- and intramolecular asymmetric Diels-Alder reaction of chiral a,p-unsaturated acyl sultams (eq 5) and has been used to catalyze a wide variety of Diels-Alder... 

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