Biomedical Engineering Reference
In-Depth Information
SCHEME 7.30
Synthesis of diastereoisomeric tetramers. Reagents and conditions: (i)
monomer
225
, HATU, DIEA, DMF/DCM; (ii) 20% piperidine/DMF; (iii) Fmoc-L-Tyr, HATU,
DIEA, DMF/DCM; (iv) 8% TFMSA/TFA, ice bath, 1.5 h; (v) precipitation from Et
2
O, then
20% piperidine/NMP, 48 h.
SCHEME 7.31
Synthesis of diastereoisomers of two different cycloadducts. Reagents and
conditions: (i)
N
-phenylmaleimide, F
3
SiPh, toluene, 40 or 60
◦
C; (ii) TFA/DCM, rt, 24 h; (iii)
dimethyl fumarate, F
3
SiPh, toluene, 40
◦
C, 48 h; (iv) dimethyl maleate, F
3
SiPh, toluene, 40
◦
C,
48 h.
