The Claisen rearrangement and its applications to organic synthesis have been studied for a long time.l In recent years, this rearrangement has been applied in stereocontrolled natural product synthesis2 and asymmetric i n d ~ c t i o n . ~ The term "Claisen rearrangement", which originally denoted the rearrangement of allyl aryl ethers to 0or p-allylphenols, has now been extended to analogous ...

Several new and know 6-(4-substituted phenyl)-4-(4-substituted phenyl)-2-phenyl-6H-1,3-thiazine (or selenazine) (Z4B7, Z4D5, Z4B7' Z4D5') were prepared by the 1,4-Michael addition reaction of chalcone derivatives with thiobenzamide or phenylselenocarboxamide in basic medium (where chalcones was formed Claisen-Schimidt condensation aromatic aldehydes 4-substituted acetophenone presence sodium hy...

in order to find the susceptibility of the claisen rearrangement and next proton shift reaction of ally) aryl etherto the substiment effects in pan position, the kinetic and the:rmodynamie parameters are calculated at the33 ltp level using 6-3110. b asis set. the calculated activation energies for the rearrangements and protonshift reactions are around 3133 kcaumol and 52.16 kcal/mol, nap.. liv...

A convergent strategy toward the synthesis of lateriflorone (5) is described. Our approach is based on biosynthetic considerations and draws on a sequence of prenylation, oxygenation and Claisen reactions for the construction of chromenequinone 6, and a tandem Claisen/Diels–Alder reaction cascade for the synthesis of caged tricycle 7. Union of fragments 6 and 7 led to the synthesis of secolater...

Bis-cyclopropanated 1,3,5-tricarbonyl compounds were prepared by a sequence of Claisen condensations and cyclopropanations. The optimization of the conditions proved to be very important to suppress retro-Claisen reactions. The conformation of these molecules was studied by experimental and computational methods. The syn/syn;syn/syn conformation is present for all derivatives. It is exclusively...