132. Creation of models designed to simulate the behavior of nature is at the core of scientific methodology, but is often neglected in undergraduate education for chemistry majors. The goal of this paper is to demonstrate that one can often "model a model".

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In contrast to the more normal reactivity of the carbon-carbon double bond in vinyl phosphonates, the oxaphospholene double bond in 5,5-dimethyl-2-phenyl-l,2-oxaphosphol-3-ene 2-oxide (7) has proven to be quite resistant to a broad spectrum of reagents including typical electrophiles, most electrophilic and nucleophilic epoxidizing reagents, and organometallic nucleophiles as well as representative Diels-Alder dienes and 1,3-dipoles.Four exceptions to this trend were iV-bromoacetamide (NBA), ozone, lithium dimethylcuprate, and sodium naphthalene. Reaction of 7 with NBA involved formation of a bromonium ion followed by methyl migration, ring opening, and dehydrobromination to give (3-keto-2-methyl-l-butenyl)phenylphosphinic acid, characterized as its methyl ester 14. Ozonolysis of 7 proceeded with cleavage of the double bond, affording (after a series of decarboxylations and oxidations) acetone, phenylphosphonic acid, and 1-carboxy-l-methylethyl phenylphosphonate

The substitution reactions of Br(CH2)nBr(1, n = 3–5) with KCN in methanol were studied in detail. Second‐order rate constants k1 [formation of the mononitrile (2) from 1] and k2 (formation of the dinitrile (3) from 2) were determined, as were the rates for the reaction of H(CH2)nBr (4, n = 3‐5) with KCN under the same conditions. The ratios k2/k1 ( = x) of the three homologs of 1 were found to be 1.15, 0.77 and 0.61 for n = 3, 4 and 5, respectively; a x value of 0.5 indicates that the functional groups behave independently. The second‐order rate constants k1 (statistically corrected) and k2 exhibit modest enhancements compared with model compound 4 when any of the following substituents are present: δ or ϵ‐bromo, γ‐, δ‐, or ϵ‐cyano. By contrast, a γ‐bromo substituent slightly retards the rate. These results indicate that the functional groups do influence each other to a modest degree by field effects which accelerate the reactions. Steric effects do not appear to play a significant role.