2001 organo-phosphorus compounds

organo-phosphorus compoundsS 0080

02 - 174Organophosphorus Compounds. Part 145. Synthesis and Reactivityof a Polycyclic, Oxa-Bridged Phosphaalkene. — Thermolysis of inde-none epoxide (I) generates a carbonyl ylide intermediate, which subsequentlyundergoes regiospecific cycloaddition to phosphaalkyne (II) to furnish the cyclicbenzofused oxa-bridged phosphaalkene (III), which exhibits an unexpectedlyhigh stability. Reaction of compound (III) with diazoacetate (IV) provides aphosphadiazole (V), probably via an unstable tricyclic cycloadduct. Additionof lithium alkoxides (VI) and (VIII) to compound (III) proceeds with excellentdiastereoselectivity to afford novel cyclic phosphinites (VII) or (IX), respectively.The stereochemical outcome strongly depends on the alkoxide used. — (RUF,SVEN G.; BERGSTRAESSER, UWE; REGITZ, MANFRED; Eur. J. Org.Chem. (2000) 12, 2219-2225; Fachbereich Chem., Univ. Kaiserslautern, D-67663Kaiserslautern, Germany; EN)

1