Ozonolysis. VIII. Alkene and Ozonide Geometry in the Alkene-Ozone Reaction

Stereospecificity in ozonide and cross-ozonide formation

“…As has already been observed by Murray, et a/.,21 the cis-trans ratios of the ozonides of various olefins are strongly influenced by the bulk of the substituents attached to the double bond. There is very little difference in the cis-trans normal ozonide ratios obtained from the cis and trans isomers of 2-butene (Table II III, experiments 20,21), or 4-methyl-2-pentene (Table III, experiments 1, 2, 5, 9, 10, 12), provided the comparison is made in the same solvent. Neither is there much difference in the cistrans ratio of 2-butene ozonide, whether it is produced as a normal or as a cross ozonide in a hydrocarbon solvent (cf. "…”

“…the cis-trans ratios of cross ozonides obtained from cis and trans unsymmetrical olefins often differ. [19][20][21] In their principal paper on stereospecificity in crossozonide formation, Murray, Youssefyeh, and Story21 state that the observed dependence of cis-trans ratios for cross ozonides on olefin geometry "is inconsistent with the Criegee zwitterion mechanism in which the zwitterion precursor to ozonide should give the same ozonide cis-trans ratios for both olefin stereoisomers in both normal and cross ozonides." In order to explain the stereochemistry of cross-ozonide formation, these authors21 propose a new mechanism, illustrated in Schemes II and III.…”

Quaternary benzylammonium rearrangements with organolithium compounds. IV. Benzyltrimethylammonium p-(tert-butyl)phenoxide with butyllithium

“…Oae and M. Kise, ibid., 1409 (1965), and references cited therein. (9) The mass spectrometer was purchased from funds provided by a National Science Foundation Research Equipment Grant. We are grateful to Miss R. Van Fossen for the mass spectra.…”

“…The infrared spectrum (KBr disk) had bands at 3700-3300 s*, 2975 w, 1715 w, 1590 m, 1110 w, 995 w, 835 m, 780 m, 775 m, and 750 m cm-1. The proton magnetic resonance spectrum of a saturated solution in hexamethylphosphoramide with a tetramethylsilane standard had chemical shifts (5 ppm, splitting s = singlet (peak integral ratio)): 1.13 s (9) CH, of ¿-butyl, 3.19 s (9) CHa on N, 4.05 s (6) H20, 4.80 s (2) CH2 of benzyl, and two complex aromatic multiplets centered at 6.57 (4) phenoxide and 7.41 (5) benzyl. (8) Association between base and salts has been shown for some lithium reagents, cf., W. Glaze and R. West, ibid., 82, 4437 (1960).…”

“…(8) Association between base and salts has been shown for some lithium reagents, cf., W. Glaze and R. West, ibid., 82, 4437 (1960). (9) Prolonged contact with silver oxide gave low yields and considerable coloration of the product. Anal.…”