Yeun-Min Tsai

GROUP TRANSFER FROM SILICON TO CARBON VIA TANDEM RADICAL CYCLIZATIONS OF ACYLSILANES

Abstract Tandem radical cyclizations of acylsilanes with alkene or alkyne functionalities attached to silicon afforded cyclic silyl ethers which were oxidatively hydrolyzed to give diols or ketone alcohols.

Intramolecular cyclizations of α-stannyl radicals to acylsilanes: regiospecific syntheses of five-membered cyclic silyl enol ethers

α-Stannyl radicals generated from acylsilanes 5, 13 and 14 cyclize to give good yields of cyclic silyl enol ethers after sequential cyclizations, radical Brook rearrangements and β-scissions.

THE FORMATION OF OXYGEN-CONTAINING HETEROCYCLES VIA INTRAMOLECULAR CYCLIZATIONS OF HALO-SUBSTITUTED ACYLSILANES AND UNSATURATED ACYLSILANES

Abstract Halo-substituted acylsilanes undergo cyclizations easily when heated in a polar solvent such as NMP to afford 2-silyldihydrofurans and 2-silyldihydropyrans. Unsaturated acylsilanes undergo cyclizations through reactions with iodine, phenylselenenyl bromide, or chloride. Further reactions of the cyclized products with pyridinium perbromide, phenylselenenyl bromide, or chloride give highly functionalized dihydrofurans and dihydropyrans.

Stereogenic reactions of the α-carbon radicals of 8-phenylmenthyl esters

The stereoselective free-radical type reduction and cyclisation of 8-phenylmenthyl esters is described; the predominant products are considered to be derived from the transition states with conformations having the larger substituent anti to the alkoxy group of the ester.