Synthesis 2011(9): 1365-1374  
DOI: 10.1055/s-0030-1259977
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Manganese(III)-Assisted Specific Intramolecular Addition

Yosuke Ito, Shunsuke Jogo, Noriko Fukuda, Ryo Okumura, Hiroshi Nishino*
Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan
Fax: +81(96)3423374; e-Mail: nishino@sci.kumamoto-u.ac.jp;
Further Information

Publication History

Received 1 February 2011
Publication Date:
30 March 2011 (online)

Abstract

Oligomethylene-tethered ω-alkenyl 3-oxobutanoates and 3-oxobutanamides underwent manganese(III)-mediated oxidative intramolecular addition to produce dihydrofuran-fused macrolides and macrocyclic amides from 8 to 26 members. A similar reaction of the oligooxamethylene-tethered ω-alkenyl 3-oxobutanoates also gave dihydrofuran-fused crown ether type macrolides which had a phase-transfer ability with sodium and potassium picrates. The manganese(III)-assisted specific intramolecular addition could be explained by the π-complexation of the ω-alkenyl part with the manganese(III) enolate.

14

When the reaction of 1 4 (0.2 mmol) with Mn(OAc)3 (1.0 mmol) was carried out for 10 min under concentrated conditions using AcOH (25 mL), the macrolide 2 4 was isolated in 85% yield (cf. Table  [¹] , entry 6). While the reaction of 1 7 (0.2 mmol) with Mn(OAc)3 (1.2 mmol) was conducted for 15 min under dilute conditions using AcOH (400 mL), the macrolide 2 7 was obtained in 50% yield (cf. Table  [¹] , entry 9).