摘要:
Four methods for the preparation of (S)-dolaphenine ((S)-2-phenyl-1-(2-thiazolyl)ethylamine, 2), which constitutes the C-terminal unit of dolastatin 10 (1) having strong anticancer activity, has been investigated. Of these, the most efficient one involved the acylation of 2-lithiothiazole with N-methoxy-N-methylphenylacetamide (8), asymmetric reduction with (+)-diisopinocampheylchloroborane (11g), followed by the modified Mitsunobu reaction utilizing diphenyl phosphorazidate.