?url_ver=Z39.88-2004&rft_id=10.1016%2FS0040-4020(02)00632-4&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Gabarda%2C+AE&rft.aulast=Gabarda&rft.aufirst=AE&rft.issue=32&rft.volume=58&rft.date=5+August+2002&rft.issn=0040-4020&rft.atitle=Asymmetric+total+synthesis+of+(20R)-homocamptothecin%2C+substituted+homocamptothecins+and+homosilatecans&rft.title=Tetrahedron&rft.pages=6329+-+6341&rft.genre=article