Enantioselective synthesis of （1S,4R）-N-（benzylcarbamoyl）- 4-aminocyclopent-2-en-l-ol by Candida antarctica lipase B

An efficient biocatalytic process has been developed to obtain optically pure （1S,4R）-N-（benzylcarba- moyl）-4-aminocyclopent-2-en-l-ol which can be used as the key intermediate of ticagrelor. In this research, several N-（benzylcarbamoyl）-4-aminocyclopent-2-en-1-ol derivatives have been investigated in which Candida antarctica lipase B （CALB） was used to catalyze the asymmetric hydrolysis reaction. As expected, some of these substrates successfully gave （l$,4R）-N-（benzylcarbamoyl）-4-aminocyclopent- 2-en-l-ol in 〉98% enantiomeric excess （ee） with conversion yields up to 45%.