ChemInform Abstract: Synthesis of 1,3‐Dioxin‐4‐ones and Their Use in Synthesis. Part 33. Cycloadditions in Syntheses. Part 57. Chiral Spirocyclic (Z)‐5‐ Arylmethylene‐1,3‐oxazine‐4,6‐diones, New Chiral Heterodienes.

Abstract

Synthesis of 1,3-Dioxin-4-ones and Their Use in Synthesis. Part 33. Cycloadditions in Syntheses. Part 57. Chiral Spirocyclic (Z)-5-Arylmethylene-1,3-oxazine-4,6-diones, New Chiral Heterodienes. -The title compounds (III) are prepared in enantiomerically pure form. The Diels-Alder reaction between (IIIa) and the ketene acetal (IV) demonstrates that the title compounds are useful heterodienes. X-ray analysis of (IIIa) reveals the existence of a 1:1 mixture of two conformers. -(SATO, M.; KITAZAWA, N.; NAGASHIMA, S.; KANEKO, C.; INOUE, N.; FURUYA, T.; Tetrahedron 47 (1991) 35, 7271-7278; Pharm. Inst., Tohoku Univ., Aobayama, Sendai 980, Japan; EN)