ChemInform Abstract: REACTIONS OF DIALKYLISOCYANATOPHOSPHITES WITH ACETOACETIC ACID ESTER

Abstract

Die Isocyanatophosphite (I) reagieren mit Acetessigsäureethylester (II) zu einem durch Hochvakuumdestillation trennbaren Gemisch aus den Isocyanato‐phosphaten (III), den 1,2‐ Azaphospholanen (IV) und den Dialkylestern der 1‐Methyl‐2‐ethoxycarbonyl‐vinyl‐ phosphonsäure (V), die in einer Z‐ und einer E‐Form vorliegen.

2‐Polyfluoroacylcycloalkanones in reactions with selected phosphorus(III) compounds

“…This may be due to the greater ring strain of the tricyclic cyclopentane phosphorane. The NMR data confirm the proposed structures of 7; the 31 P NMR shift values are typical for tricyclic phosphoranes [7,9,18], appearing at significantly lower field for the cyclopentane derivative 7b (δ P = −35.76) than for cyclohexane derivative 7a Pentane-2,4-dione and tris(trimethylsilyl)aminoiminophosphine gave similarly two diastereomeric 2-imino-1,2-5 4 -oxaphosphol-4-ene (8b) (Scheme 7) in a 33:67 ratio, which however changes drastically after distillation to ca. 8:92.…”

“…The resulting adduct has two possibilities for further stabilization; either a ring closure to furnish a phosphorane ( 3 3 P → 5 5 P, type A) [1,2,[6][7][8][9] or a substituent migration 97 from the phosphite with formation of a phosphonate 3 3 P → 5 4 P, type B) [1,2,[10][11][12]. The reaction of 2-trifluoroacetylcyclohexanone (1a) with tris(trimethylsilyl) phosphite yields via nucleophilic attack of phosphorus at the trifluoroacetyl carbonyl carbon atom, followed by silatropy [10,13,14], a mixture of phosphonates 2a and 2b (94:6) according to type B (Scheme 1).…”

“…Unlike its linear analog (ethyl 4,4,4-trifluorobutan-3-onate) [11], ␣-trifluoroacetyl-␦-valerolactone does not react with diethyl isocyanatophosphite. Surprisingly, only starting compounds are isolated from the reaction of pentane-2,4-dione with diethyl isocyanatophosphite.…”