Development of Conjugate Addition of Lithium Dialkylcuprates to Thiochromones: Synthesis of 2-Alkylthiochroman-4-ones and Additional Synthetic Applications
Lithium dialkylcuprates undergo conjugateaddition to thiochromones to afford 2-alkylthiochroman-4-ones in good yields. This approach provide an efficient and general synthetic approach to privileged sulfur-containing structural motifs and valuable precursors for many pharmaceuticals, starting from common substrates-thiochromones. Good yields of 2-alkyl-substituted thiochroman-4-ones are attained with
Reactions of organocuprates with vinyl-triflates and related cephems: A novel approach to 3-substituted cephalosporins
作者:Joydeep Kant、Chester Sapino、Stephen R. Baker
DOI:10.1016/s0040-4039(00)97404-5
日期:1990.1
Vinyl-triflates and related 3-substituted cephems readily undergo addition-elimination reactions with a variety of organocuprates to form new carbon-carbon bonds. This chemistry presents a novel approach to the synthesis of 3-alkyl, 3-aryl, and 3-alkenylcephalosporins.
[reaction: see text]. A convergent totalsynthesis of the methyl ester of zincophorin, an ionophore antibiotic, has been realized relying on a diastereoselective titanium-mediated aldol coupling between the C1-C12 and C13-C25 subunits. The latter fragment was prepared by using a Carroll-Claisen rearrangement.
SYNTHETIC UTILITY OF ALLYLIC THIOLCARBAMATES. STEREOSELECTIVE SYNTHESIS OF SIMPLE NATURAL PRODUCTS INCLUDING OPTICALLY ACTIVE MANICONE AND β-SINENSAL
作者:Tetsuya Mimura、Yasuhiro Kimura、Takeshi Nakai
DOI:10.1246/cl.1979.1361
日期:1979.11.5
Stereoselective syntheses of the two opticallyactive pheromones of ants, (+)-(E)-4,6-dimethyl-4-octen-3-one (manicone) and (+)-(E)-2,4-dimethyl-2-hexenoic acid, and of β-sinensal and (E)-β-farnesene are described in which allylic thiolcarbamates readily derived from allylic alcohols via the [3,3]sigmatropic rearrangement were used as the key intermediates.
Two types of stereocontrol in the formation of spiro skeletons via a carbonyl ene reaction and a palladium-catalysed carbonyl allylation: a formal synthesis of (+)-perhydrohistrionicotoxin
Different stereocontrol is observed in the formation of spiro skeletons via a carbonyl ene reaction and a palladium-catalysed carbonyl allylation, and a formal synthesis of (+)-perhydrohistrionicotoxin is accomplished.