An Efficient Enzymatic Synthesis of Benzocispentacin and Its New Six‐ and Seven‐Membered Homologues

• Published in: Chemistry – A European Journal
• Main Authors: Forró, Enikő, Fülöp, Ferenc
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2006
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/chem.200501286; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fchem.200501286; https://onlinelibrary.wiley.com/doi/full/10.1002/chem.200501286

Abstract A very efficient enzymatic method was developed for the synthesis of new enantiomeric benzocispentacin and its six‐ and seven‐membered homologues through the Lipolase (lipase B from Candida antarctica ) catalyzed enantioselective ( E >200) ring opening of 3,4‐benzo‐6‐azabicyclo[3.2.0]heptan‐7‐one, 4,5‐benzo‐7‐azabicyclo[4.2.0]octan‐8‐one, and 5,6‐benzo‐8‐azabicyclo[5.2.0]nonan‐9‐one with H 2 O in i Pr 2 O at 60 °C. The (1 R ,2 R )‐β‐amino acids ( ee ≥96 %, yields≥40 %) and (1 S ,6 S )‐, (1 S ,7 S )‐, and (1 S ,8 S )‐β‐lactams ( ee >99 %, yields≥44 %) produced could be easily separated. The ring opening of racemic and enantiomeric β‐lactams with 18 % HCl afforded the corresponding β‐amino acid hydrochlorides.