Syntheses of doubly linked proanthocyanidins using free flavan units as nucleophiles: insight into the origin of the high regioselectivity of annulation. Issue 41 (4th October 2019)

• Record Type: Journal Article
• Authors: Betkekar, Vipul V.; Harachi, Mio; Suzuki, Keisuke; Ohmori, Ken
• Is Part Of: Organic & biomolecular chemistry. Volume 17:Issue 41(2019)
• Page Start: 9129
• Page End: 9134
• Publication Date: 2019-10-04
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c9ob01896d
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Reported herein is a viable synthesis route to procyanidins A1 and A2, doubly linked flavan dimers. The use of nascent nucleophilic partner, catechin or epicatechin, enabled facile regioselective annulation with an ethylenedioxy-bridged flavan unit. Abstract : A synthesis method of doubly linked flavan dimers is reported via the acid-promoted annulation reaction using nascent catechins, (+)-catechin or (−)-epicatechin, as a dianionic partner and an ethylenedioxy-bridged flavan as a dicationic partner. Procyanidins A1 and A2 were synthesized. On the high regioselectivity of the annulation reactions, model experiments and computational studies were carried out.