Enantioselective total synthesis of pyrrolo-[2, 1-c][1, 4]-benzodiazepine monomers (S)-(−)-barmumycin and (S)-(+)-boseongazepine B. Issue 16 (10th July 2018)

• Record Type: Journal Article
• Authors: Bhosale, Viraj A.; Waghmode, Suresh B.
• Is Part Of: Organic chemistry frontiers. Volume 5:Issue 16(2018)
• Page Start: 2442
• Page End: 2446
• Publication Date: 2018-07-10
• Subjects: Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1039/c8qo00446c
• Languages: English
• ISSNs: 2052-4110

Abstract

Abstract : An efficient enantioselective total synthesis of pyrrolo-[2, 1- c ][1, 4]benzodiazepine (PBD) monomers ( S )-(−)-barmumycin and ( S )-(+)-boseongazepine B was achieved through a stereocontrolled strategy, which relies on a proline catalysed asymmetric α-amination and ester α-ethylenation. Abstract : An efficient enantioselective total synthesis of pyrrolo-[2, 1- c ][1, 4]benzodiazepine (PBD) monomers ( S )-(−)-barmumycin and ( S )-(+)-boseongazepine B and collective formal total syntheses of oxoprothracarcin, prothracarcin and ( S )-(+)-boseongazepine C are described. The present approach is based on an efficient construction of an ethylidene substituted C-4 pyrrolidine core, that is the stereocontrolled introduction of a trisubstituted double bond through simple enolate α-alkylation of an ester, which also relies on a proline catalysed asymmetric α-amination followed by HWE olefination. The present synthetic route possesses superior stereocontrol over the C-4 ethylidene substituent as well as the C-( S ) stereogenic center, which allows more functional variations on the five-membered prolinol core as compared to the existing PBD synthesis.