Noriyoshi Inukai

Cycloadditions in syntheses. Part 41. Chiral spirocyclic 5-arylmethylene-1,3-dioxane-4,6-diones as novel synthons for enantiomerically pure 2-arylcyclopropane-1,1-dicarboxylates☆

Abstract E- and Z-isomers of spirocyclic 5-arylmethylene-1,3-dioxane-4,6-dione, useful synthons for enantiomerically pure cyclopropane-1,1-dicarboxylates, have been synthesized from 1-menthone. Their diastereofacial selectivity is explained by a boat conformation in their dioxanedione ring.

Synthesis of 1,3-dioxin-4-ones and their use in synthesis. 21.1 Intramolecular photo [2+2] cycloaddition reactions of chiral spirocyclic dioxinones having ω-alkenyl groups at 3-position2

Chiral spirocyclic dioxinones having an ω-alkenyl group at 3-position were synthesized and their intramolecular photo[2+2]cycloaddition reactions were examined. The results not only provide enantioselective synthetic route to 2S-acetonylcyclohexanecarboxylic acids but also clarify the reason why these dioxinones exhibit remarkable diastereofacial selectivities in both intra- and intermolecular photo[2+2]cycloaddition reactions