Andrew ratz Daphniphyllum Alkaloids Evans Group Seminar, June 1993 Proposed biosynthesis contd Retrosynthesis of Methyl Homosecodaphniphyllate CHO OR O2H CO2H OR 2D-0412/110011:31AMAndrew Ratz Daphniphyllum Alkaloids Evans Group Seminar, June 1993 Squalene 7 10 14 15 3 + Proposed Biosynthesis cont'd Daphnilactone A + + H+ + iPr HN Me CO2H Me HO CHO OP* CO2H N Me iPr N HO Me OP* H OP* Me HO N N iPr Me CO2H CO2H H N Me iPr N HO Me OP* iPr CO2Me N O O iPr N Me CO2H HN Me iPr Me Me Me Methyl Homodaphniphyllate + + + + + Retrosynthesis of Methyl Homosecodaphniphyllate iPr HN Me CO2Me HN Me OR OR N Me N H H N Me OR OR Me Me Me H OHC Me Me Me OR OHC Me I Me Me R” O R’ OR O 32D-04 12/11/00 11:31 AM