Diketones from ozonolysis of fused 3‐phospholene oxides: Cyclizations to 3‐phosphorinone and to 1,4‐dihydro‐1,4‐azaphosphinine derivatives

Abstract

I -= Me or Ph) were prepared and ozonized at -78°C to give diketones in good yield. The intramolecular aldol condensation was performed on certain o f these ketones to give multicyclic 3-phosphorinone derivatives. I n some cases, double-bond rearrangement into the ring-f'usion position was encountered. The I-phenyl derivative in the benzophosphindole series could not be cyclized due to ready displacement of the P fragment from the tetralone system. The diketones reacted with ammonium acetate to give multicyclic derivatives of the 1,4-dihydro-l,4-azaphosphinine ring system. 1,2,3,4,5,6,7,8-0ctahydro-3-oxo-l -phenylphosphinoline I-oxide was used to demonstrate the value o f the bicyclic 3-phosphorinones as precursors of I-phosphadecalone derivatives. The carbonyl group was protected as the ethylene ketal and the double bond (as well as the benzene ring) was hydrogenated with ease. Hydrolysis gave the l-phospha-3decalone derivative. Reduction o f the same 3-phosphorinone with NaBH4 gave a mixture of diastereomeric alcohols.

Studies of Cobalt Particle Size Effects on Fischer–Tropsch Synthesis over Core–Shell‐Structured Catalysts

“…The residue was purified by silica gel flash column chromatography (pentane) to give diene 4 (1.18 g, 60 %) as a colorless liquid. The characterization data were in agreement with those reported 11…”

Azaphosphinines and their derivatives

“…By 1990, Quin and Marsi published a more comprehensive work on phosphorus heterocycles derived from more exotic bis-β-keto-phosphane oxides 188 and 189 (Scheme 70). 121 While many of these species do not fit the scope of this review, there were a few interesting examples that explore the possibilities of extension via saturated ring fusion such as 190 and 191 .…”