ヘック反応
Detosylation of 11 (sodium naphthalenide) and amidation with acid chloride 3-bromoacryloyl chloride gave amide 12 and another Heck reaction gave pentacycle 13. double bond isomerization (sodium / iPrOH), Boc group deprotection (triflic acid) and amine alkylation with "(Z)-BrCH2CICH=CH2OTBDMS" (see Rawal) gave compound 14 (identical to one of the Vollhardt intermediates). A final heck reaction (15) and TBDMS deprotection formed (−)-isostrychnine 16.