Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products

• Sultan Taskaya,
• Nurettin Menges and
• Metin Balci

Beilstein J. Org. Chem. 2015, 11, 897–905, doi:10.3762/bjoc.11.101

• hemiacetals after cascade reactions. Keywords: alkyne cyclization; gold-catalyzed reaction; indolo-oxazin-1-one; marine natural products; pyrrolo-oxazin-1-one; Introduction Pyrrole-containing heterocycles are widely distributed within a large number of natural products and biologically active molecules [1

• structure 6 or 7 was not formed. After failure of the cyclization reaction of 13 with AuCl3, even in water-free solvents, we turned our attention to the construction of the pyrrolo-oxazin-1-one skeleton with the corresponding acid 15. For this purpose, the propargyl ester 13 was first hydrolyzed with K2CO3