1.2- oxaphosphol-3-ene 2-oxides

Some reactions of 1,2-oxaphosphol-3-ene 2-oxides have been reported. When brominated under free radical conditions,... 

The action of elemental chlorine on diethyl propadienylphosphonate yields an inseparable mixture of diethyl (3-chloroprop-l-ynyl)phosphonate (about 30%), diethyl (E)- and (Z)-(2,3-dichloroprop-l-enyl)phosphonate (in yields of 12% and 9%, respectively) and 4-chloro-2-ethoxy-1,2-oxaphosphol-3-ene 2-oxide (29%) when a single hydrogen atom on C(i) or C(3) is replaced by a methyl group, the yields of the respective 4-chloro-l, 2-oxaphos-phol-3-ene 2-oxides are about 75%... 

The phenylphosphonic acid 197 reacts with 5 equiv. of AgC104 to deliver the 1,2-oxa-phosphol-3-ene-2-oxide 198 in an 80% total yield of the Z- and E-isomers (Scheme 15.63) [127]. For related reactions, see also [128]. With a phosphonic acid and Hg(OAc)2, the mercurated intermediate, a 4-acetoxymercury l,2-oxaphosphol-3-ene and the corresponding chloride after ligand exchange were isolated [129]. 

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