Hexahydro-1,3-benzoxazines, synthesis

Two types of dihydro-l,3-oxazinones are relevant to the discussed topic the e -fused hexahydro-2//-l,3-benzoxazin-4-ones and their homologs, and the d -fused hexahydro-2//-3,l-benzoxazin-4-ones and their homologs. For the synthesis of these derivatives, just two methods are known. 

A. Horti, D.E. Redmond, R. Soufer, No-carrier-added (nca) synthesis of 6-[F-18] fluoro-L-DOPA using 3,5,7,8,8a-hexahydro-7,7,8a-trimethyl-[6S-(6-alpha, 8-alpha, 8-alpha-beta]-6,8-methano-2H-1,4-benzoxazin-2-one, J. Label. Compds Radiopharm. 36 (1995) 409 23. 

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