(E)- or (Z)-Enynoic acids and (2E,4E)- or (2Z,4E)-dienoic acids can be obtained in good yields under mild conditions through palladium-catalysed cross coupling of (E)- or (Z)-3-iodoprop-2-enoic acid with alkynylzinc or vinyltin reagents.
SYNTHETIC UTILITY OF A FLUORINE-FACILITATED CLAISEN REARRANGEMENT: A NOVEL SYNTHETIC METHOD FOR 2,4-ALKADIENOIC ACIDS USING 2,2,2-TRIFLUOROETHYL PHENYL SULFOXIDE
A novel synthetic method for 2,4-alkadienoic acids from allylic alcohols and 2,2,2-trifluoroethyl phenyl sulfoxide is described which involves the in situ Claisen rearrangement facilitated by the fluorine. This method was applied to the stereocontrolled synthesis of pellitorine, a natural insecticide.
Regio- and diastereoselective boron-mediated aldol reactions of chiral α,β,γ,δ-unsaturated N-acyloxazolidinones
作者:James M Takacs、Mohamad R Jaber、Benjamin J Swanson、Steven J Mehrman
DOI:10.1016/s0957-4166(98)00459-5
日期:1998.12
Chiral N-acyloxazolidinones derived from conjugated dienoic acids undergo boron-mediated aldol condensation in good yield and with high regio- and diastereoselectivity to provide a convenient method for introducing a 1,3-diene subunit. The condensation of a homologous triene derivative is also described.
Larvae of the leafbeetlesPhaedon amoraciae, Phaedon cochleariae, Gastrophysa viridula, and Plagiodera versicolora biosynthesize the two iridoids chrysomelidial 1 and/or plagiodial 3 from geraniol 7 by an oxidative sequence related to that known from plants en route to the iridane skeleton. Following ω-oxidation of geraniol 7 the resulting 8-hydroxygeraniol 8 is oxidized further to 8-oxocitral 9.
The substrate scope of dehydratases in antibiotic biosynthesis and their application in kinetic resolutions
作者:Zhiyong Yin、Daniel Bär、Bertolt Gust、Jeroen S. Dickschat
DOI:10.1039/d2ob01879a
日期:——
The dehydratase BorDH2 from borrelidin biosynthesis was found to have a wide substrate tolerance in the dehydration of 3D alcohols and was applied in kinetic resolutions.