Diels-Alder Reactions of α,β-Unsaturated Thioesters and α,β-Unsaturated Selenoesters

Abstract

α,β-Unsaturated thioesters and selenoesters serve as dienophiles in Diels-Alder reactions with a variety of 1,3-dienes. Good levels of regioselectivity are obtained with unsymmetrical dienes when Lewis acid promoters are used. Thioesters and selenoesters are more reactive than the corresponding methyl esters based on competition experiments with cyclopentadiene.

Chemistry of Acyl Radicals

“…This new reaction obviously provides a convenient entry into selenoesters of various substituted 4-cyclohexene carboxylic acids. 144 …”

Diastereoselective Total Synthesis of (±)‐Schindilactone A

“…The intermolecular Diels-Alder reaction of 5 with 6 was carried out with Et 2 AlCl as the catalyst, [12] and ketone 7 was obtained in 65 % yield. and treatment of 8 with KHMDS in THF and subsequent reaction with O 2 in the presence of P(OMe) 3 [13] gave a tertiary alcohol in 75 % yield. Thus, vinyl silyl ether 9 was obtained in 95 % yield after reaction of the tertiary alcohol with TESOTf and 2,6-lutidine in CH 2 Cl 2 .…”

Se‐Phenyl Prop‐2‐eneselenoate: An Ethylene Equivalent for Diels–Alder Reactions

“…We then studied the Diels–Alder reactions of 2 . Hart et al 12. had shown that selenoacrylates are much more reactive than normal acrylates, presumably owing to poorer overlap between the selenium atom and the carbonyl group, thereby making the carbonyl group more ketone‐like rather than ester‐like.…”