Regioselective and stereoselective syntheses of 1,2,3-triaminocyclohexane derivatives

The reactions of trans- and cis-3-bromo-1,2-epoxycyclohexanes with pyrrolidine are described. While in the case of the trans-epoxide 2 the diamino alcohol 3 was obtained in benzene, the cis-epoxide 5 unexpectedly led to bromo amino alcohol 7 in benzene. Compound 7 could be converted to 3 using pyrrolidine in DMF. The trans-3-chloro-1,2-epoxycyclohexane 11 was the source of the isomeric diamino alcohol 4. The diamino alcohols 3 and 4 were used to produce triamines containing two pyrrolidine and one methylamine residues (14, 15, 22). The bromo amino alcohol 7 was used to prepare a triamine containing two methylamine and one pyrrolidine residues (25). The triamines were converted to amide derivatives. The structure of one of these amides (23) was confirmed by single crystal X-ray analysis.