The synthesis of various types of optically active α-(allenylsilane-containing)glycines via a chirality-transferring ester-enolate Claisen rearrangement of α-acyloxy-α-alkynylsilanes is described. The conversion of the rearranged products into the optically active silicon-free α-(allenyl)- and α-substituted-α-(allenyl)glycines was achieved by the removal of the Me2PhSi- or TMS group from the allene
Tetrasubstituted Allene Ethers; Synthesis and Use in Nazarov Reactions
作者:Marcus A. Tius、Bradley K. Tokeshi
DOI:10.1055/s-2004-815994
日期:——
A method for the synthesis of tetrasubstituted allene ethers is described, making use of a reverseBrookrearrangement in the key step. The allene products have been used in the Nazarov cyclization reaction.
The Au(I)-catalyzed cyclization of an allenylglycine, which possessed a silyl group attached to the opposite side of the allenic terminus, occurred at the allenic center to produce the 2-amino-4-silylmethylene-substituted gamma-butyrolactone 2a in a highly regio- and stereoselective manner. The presence of a silyl group at the allenic terminus is crucial for the present 5-endo-dig gamma-butyrolactonization. (C) 2011 Elsevier Ltd. All rights reserved.