A Short and Efficient Synthesis of <scp>l</scp>-5,5,5,5‘,5‘,5‘-hexafluoroleucine from <i>N</i>-Cbz-<scp>l</scp>-Serine
作者:James T. Anderson、Peter L. Toogood、E. Neil G. Marsh
DOI:10.1021/ol026922j
日期:2002.11.1
[GRAPHICS]5,5,5,5',5',5'-Hexafluoroleucine (6), a fluorous analogue of leucine, is of considerable interest as a building block in the design of fluorous proteins and peptides. We report a short and efficient synthesis of 6, which is obtained from N-Cbz-L-serine (1) in 50% overall yield, 99% enantiomeric excess, and In multigram quantities. Key steps are addition of a serine-derived organozincate to hexafluoroacetone to construct the hexafluoroleucine side chain, followed by radical-mediated deoxygenation of the resulting tertiary alcohol.