A tyrosine-derived benzofuranone related to diazonamide A.

[formula: see text] Cyclization of 8 with PPA followed by MCPBA oxidation affords the benzofuranone 10. Treatment with a chiral chloroformate in the presence of DMAP affords the target benzofuranone 13 via an enol ester 12.

[1]  E. Vedejs,et al.  Progress toward synthesis of diazonamide A. Preparation of a 3-(oxazol-5-yl)-4-trifluoromethyl-sulfonyloxyindole and its use in biaryl coupling reactions. , 2000, Organic letters.

[2]  P. Magnus,et al.  Synthesis of benzofuranones related to diazonamide via an intramolecular Pummerer reaction , 1999 .

[3]  P. Harran,et al.  Macrocyclic Triarylethylenes via Heck Endocyclization: A System Relevant to Diazonamide Synthesis , 1998 .

[4]  A. Boto,et al.  A synthetic approach towards the aromatic macrocyclic core of diazonamide A based on sp2-sp2 coupling protocols , 1998 .

[5]  P. Wipf,et al.  Synthetic studies toward diazonamide A. Preparation of the benzofuranone-indolyloxazole fragment , 1998 .

[6]  C. Moody,et al.  Synthesis of heterocyclic natural products: Model studies towards diazonamide A , 1994 .

[7]  J. Whitesell.  Cyclohexyl-based chiral auxiliaries , 1992 .

[8]  William Fenical,et al.  Isolation and Structure Determination of Diazonamides A and B, Unusual Cytotoxic Metabolites from the Marine Ascidian Diazona chinensis , 1991 .

[9]  S. Arrivo,et al.  4-(Dimethylamino)pyridine as a catalyst for carbon acylation. 2. Control of carbon vs. oxygen acylation in benzofuranones , 1987 .

[10]  C. Moody,et al.  Studies towards the synthesis of diazonamide A. Unexpected formation of a 3,4-bridged indole , 1997 .

[11]  H. Nagase,et al.  Metal-halogen exchange between polybromoanisoles and aliphatic Grignard reagents: a synthesis of cyclopenta[b]benzofurans , 1992 .