2- Trimethylsilyloxybuta-l ,3-diene

IPreparation of 2-trimethylsilyloxybuta-l,3-diene and Diels-Alder addition Iwith diethyl fumarate. 

A Lewis acid-catalyzed cyclization of 2-aza-3-trimethylsilyloxybuta-l,3-diene has been reported in 2003 and the stereochemical differences with the uncatalyzed... 

Researchers in Chile have recently shown that treatment of the product obtained from condensation of 2-cyano-l,4-benzoquinone with (E)- -trimethylsilyloxybuta-1,3-diene with dilute hydrochloric acid results in smooth, high yielding conversion to the dihydrobenzofuran 1. 

Diels-Alder Cycloadditions.—The range of functionalized diene systems, displaying regioselective behaviour in the Diels-Alder reaction, continues to expand. Notable new additions include l-phenylseleno-2-trimethylsilyloxy-4-methoxybuta-l,3-diene (82) and the isomers 1- and 2-methyl-l,3-bis(trimethylsilyloxy)buta-l,3-dienes (84) and (85). The diene (82) is readily derived from l-methoxy-3-trimethylsilyloxybuta-1,3-diene (81) and provides a direct route to the synthetically valuable 4-acylcyclohexa-2,5-dienones (83), whereas dienes (84) and (85) react with activated dienophiles (e.g. RCH=CHC02Et) in good yield, leading to keto-esters of the type (86) on hydrolysis. 

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