Synthesis 2007(18): 2887-2893  
DOI: 10.1055/s-2007-983848
PAPER
© Georg Thieme Verlag Stuttgart · New York

Enantioselective Synthesis of an Analogue of Nanaomycin A

Margaret A. Brimble*, Prabhakar Bachu, Jonathan Sperry
Department of Chemistry, University of Auckland, Private Bag 92019, 23 Symonds Street, Auckland, New Zealand
Fax: +64(9)3737422; e-Mail: m.brimble@auckland.ac.nz;
Further Information

Publication History

Received 30 May 2007
Publication Date:
08 August 2007 (online)

Abstract

The enantioselective synthesis of (1R,3R)-deoxynanaomycin A (4) is reported. The key step involves introduction of the stereocenter in (S)-homoallylic alcohol 10a using an asymmetric allylation of aldehyde 9. Lithium-halogen exchange of bromo acetate 11 triggered rapid intramolecular cyclization furnishing lactol 12 that underwent silane-mediated reduction providing (1R,3S)-naphthopyran 13. Dihydroxylation and oxidative cleavage gave aldehyde 15 that underwent two successive oxidations delivering (1R,3R)-deoxynanaomycin A (4) in high enantiopurity and an overall 7% yield over 12 steps from 1-naphthol (5).