Synthesis of .alpha.,.beta.-unsaturated carbonyl compounds by palladium(II)-catalyzed dehydrosilylation of silyl enol ethers

Synthetic Studies of Natural 10-Membered Lactones, Mueggelone, Microcarpalide, and Sch 642305, Which Have Interesting Bioactivities

“…In the same manner as in Wilson' s synthesis, 91) bicyclic lactone 77 was converted to Sch 642305 via Saegusa-Ito unsaturation. 97) They succeeded in concise synthesis, and the stereoselectivity was excellent. [6]).…”

“…They stated that the corresponding anti-isomer was presumably lost at the RCM step. Finally, the enone moiety was constructed by SaegusaIto unsaturation, 97) and deprotection completed the target molecule. Thus they succeeded in short-step synthesis of Sch 642305.…”

Syntheses of Fumagillin and Ovalicin

“…TBS protection of alcohol 76, and subsequent hydroboration of the terminal olefin gave a primary alcohol, which was then oxidized to aldehyde 77. Conversion to the a,b-unsaturated aldehyde by Ito-Saegusa oxidation, [50] aldehyde reduction with DIBAL-H, and desilylation by using TBAF gave allylic alcohol 78. The primary alcohol moiety in 78 was then selectively protected as its TBS ether, and oxidation of the secondary alcohol gave ketone 79.…”

A conjugate addition-dipolar cycloaddition approach towards the synthesis of various alkaloids

“…Reaction of the secondary amine with benzoyl chloride gave amide 32 which was converted to 2,3-dihydropyridinone 33 by means of Saegusa oxidation. 41 Introduction of the final stereocenter was carried out by conjugate addition of copper complexed-pentylmagnesium bromide onto the π-system of the vinylogous amide 33. This reaction provided piperidone 34 in excellent yield.…”