Highly regioselective diels-alder reactions of 2-trimethylsilylmethyl- 1,3-butadiene catalyzed by a lewis acid and applications to syntheses of terpenes

✍ Scribed by Akira Hosomi; Hirokazu Iguchi; Jun-ichi Sasaki; Hideki Sakurai

• Book ID: 104220386
• Publisher: Elsevier Science
• Year: 1982
• Tongue: French
• Weight: 232 KB
• Volume: 23
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)86886-0

✦ Synopsis

2-Trimethylsilylmethyl-1,3_butadiene undergoes highly regioselective Diels-Alder reactions with dienophiles such as acrolein and methyl vinyl ketone catalyzed by aluminum chloride in which the "para" isomers are obtained almost exclusively. The adducts are converted readily to a variety of naturally occurring mono and sesquiterpenes.

Previously we have described that 2-trimethylsilylmethyl-1,3-butadiene(&) is not only an efficient and convenient reagent for the regiospecific isopreny-lation2 but also an excellent diene for the highly regio-and stereoselective Diels-Alder reactions with unsymmetrical dienophiles.

3 We now report that the Lewis acid-catalyzed reaction of A with methyl vinyl ketone, acrolein and acrylic esters gives almost pure "para" adducts( and that the adducts are useful and convenient precursors for the synthesis of natural terpenes.