?url_ver=Z39.88-2004&rft_id=10.1021%2Fol048252i&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Wipf%2C+P&rft.aulast=Wipf&rft.aufirst=P&rft.issue=22&rft.volume=6&rft.date=28+October+2004&rft.issn=1523-7060&rft.atitle=Synthesis+of+the+tubuvaline-tubuphenylalanine+(Tuv-Tup)+fragment+of+tubulysin&rft.title=Organic+Letters&rft.pages=4057+-+4060&rft.genre=article