Propyl-isome

Although the 11a- and /3-epimers of 3,ll-dimethyl-6-propyl-8-hydroxy-benzomorphans were synthesized and evaluated as analgesics in the early 1960s,(40,41) the corresponding 6-methyl-lla and 11/3-propyl isomers were not synthesized until 1975, when May s group(42) prepared the key pyridine intermediate, 4-methyl-3-propylpyridine, from the condensation of cyanoacetamide and ethyl 2-propylacetoacetate in methanolic potassium hydroxide. 

Reduction of the cation (M = W) with NaBH4 affords a yellow oil identified as the isopropyl complex (C5H6)W(CO)3[CH(CH3)2] with none of the w-propyl isomer present. A hydride ion addition corresponding to that with the analogous iron complex (255) is postulated. 

He also observed that there are only four methylene dioxy phenyl (MDP) synergists used commercially in the United States PBO, Sulphoxide, /V-Propyl Isome and Tropilal. PBO, introduced in 1947, dominates. ... 

The volatilization of isopropylacrylate [113-115] is a two-stage process as indicated by the thermogram in Fig. 38. No alcohol is formed and the ratio of C02 to propene is lower than unity. The polymer becomes insoluble and brittle and a yellow colouration appears. The volatilization occurs at a lower temperature for this polymer than for the rc-propyl isomer described earlier (Fig. 36). Anhydride structures and water were detected by means of infrared spectra. 

Propylbenzene is o-hydroxylated at a rate comparable with that for the 1-propyl isomer in Ref. [31]. Triphase catalysis. Benzyl chloride/HjO molar ratio 3. 

In most cases, complexes of primary alkyl ligands are more stable than the isomeric complexes of secondary or tertiary alkyl ligands. For example, Reger has shown that the secondary butyl iron complex in Equation 3.18 isomerizes to the corresponding primary n-butyl complex, and that the isopropyl palladium complex in Equation 3.19 isomerizes to the more stable -propyl isomer. Likewise, secondary zirconocene alkyl complexes isomerize to the linear isomers (Equation 320), as shown many years ago by Schwartz, and Labinger and Bercaw have recently shown that the sec-butyl complex of zirconocene, generated by the hydrozirconation of cis-2-butene, isomerizes in several hours to the corresponding n-butyl complex. ... 

Tetrahydro-3-methyl-6,7-methylenedioxy-naphthalene-1,2-dicarboxylic acid, di-n-propyl ester (n-propyl isome)... 

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