Biomimetic Alkaloid Syntheses. 15. Enantioselective Syntheses with Epichlorohydrin: Total Syntheses of (+)-, (-)-, and (+/-)-Vindoline and a Synthesis of (-)-Vindorosine

Article abstract of DOI:10.1021/jo00379a006

Total syntheses of vindoline (1) in racemic as well as in each enantiomeric form and of (-)-vindorosine (2) are described.They were achieved by generation and diastereoselective cyclizations of 14-hydroxysecodine intermediates 6 and 7.The subsequent oxidative elaboration of ring E was also studied with 3-oxotabersonine (24), 3-oxovincadifformine (26), and 14β-hydroxyvincadifformine (15).N^a-Methyltabersonine (22) was oxidized to a ring-D-contracted α-keto lactam, 23.