Electron-transfer-induced photochemical reactions of (silylallyl)iminium and benzylpyrrolinium salts by dual diradical and diradical cation cyclization pathways
作者:In Seop Cho、Chung Lan Tu、Patrick S. Mariano
DOI:10.1021/ja00165a052
日期:1990.4
The electron-transfer-induced photocyclization reactions of a series of N- and C-silylmethallyl-substituted iminium and 1-benzyl-1-pyrrolinium salts have been investigated in order to gain information about their mechanistic course and to probe their synthetic potential. The results obtained from these studies demonstrate that diradical cation intermediates formed in these processes can be transformed
Engineering Acyclic Stereocontrol in the Alkylation of Vinylglycine-Derived Dianions: Asymmetric Synthesis of Higher α-Vinyl Amino Acids
作者:David B. Berkowitz、Jill M. McFadden、Marianne K. Sloss
DOI:10.1021/jo9918091
日期:2000.5.1
auxiliary may be recovered in high yield (generally 90%) using a modification of Gassman's "anhydrous hydroxide" conditions, in which considerably higher temperatures are employed. Among the sidechains introduced directly are those of butyrine, leucine, ornithine, phenylalanine, aspartate, valine, and norvaline. The lysine sidechain is elaborated via a 4-step sequence from the alkylation product obtained