Question

Write a complete curved-arrow mechanism for all steps in the following transformation.

H NH2 1. NaCN, HCN, pH 5 2. H30+, H20 HO NEC O (+/-) (+/-)

Answer 1

i protonation of carbonyl group ht HO NH2 904 ܫܡq NH2 Cilj nucleophilic addition of NHy onto C20 H -Ht H -NH₂ H HO H-.. Hit fit +17 ME that Intermediate Formation of iminium Ion from the intermediate H Lot

Attack of EN on to the electrophilic iminium son CAF L NC + t Ca can attack on either face of C=N =) weget + both enantioners Protonation of CEN group. ho CNECT 4- OH₂ t toH2 ht | 14+ HN HAJI wer H H. OK ton MJI Hora 'M H É h