Solvolysis of alkyl diazotates. VI. Stereochemical dissection of return and exchange pathways

Abstract

Optically active octane 2-diazotate (160) was hydrolyzed with H2180. Product 2-octanol was converted to the l-acetyl lactate diastereomers, which were separated by glpc and analyzed for l80 content by mass spectroscopy. From the (glpc) stereochemical data and the lsO analyses, 2-octanol formation could be partitioned into four pathways: 160 conservation-retention, 160 conservation-inversion, 160 exchange-retention, and lsO exchange-inversion. The percentages corresponding to the above pathways, for the H2180 hydrolysis of dry octane 2-diazotate (leO) were 26.6, 16.7, 13.8, and 43.1%, respectively. The results are discussed in terms of an intermediate cationic 2-octyl moiety which largely fails to become symmetrically hydrated before collapse to 2-octanol. Consequences for the study of deamination reactions are highlighted.

A Half‐Century Odyssey in the Realm of Reactive Intermediates

“…With chiral R groups (e.g., 2-octyl derived from 2-aminooctane) and water- 18 O as the hydrolytic medium (while the diazotate oxygen was the normal 16 O), product 2-octanol could be partitioned between four different pathways of formation: 16 O-conservation with (stereochemical) retention, 16 O-conservation with inversion, 18 O-incorporation with retention, and 18 O-incorporation with inversion. [12] These results fit the mechanistic pattern of solvolysis via ion pairs then emerging in physical organic chemistry, [13] while extending the mechanism to a case where the leaving group and solvent nucleophile were degenerate.…”

Chemistry of carbamates. VIII. Pathways in the base-catalyzed decomposition of cyclic N-nitroso carbamates

“…The quantitative estimation of the reaction products was carried out by gc on a 30% SE-30 column. 12 All the products [11][12][13][14][15][16] were identified by either nmr comparison with authentic materials or a combination of nmr, ir, and mass spectra and elemental analysis. Some of the stereoisomers were isolated and analyzed only as a cistrans or threo-erythro mixture (e.g., 12,15).…”

The chemistry of nitrosoamides

“…With the proper choice of conditions, base catalyzed decompositions of nitrosoamides can bo adapted to the study of alkyl deaminations (77). In an interesting scries of experiments, Moss and co-workers (17)(18)(19)(20) studied the stereochemical return and solvolysis pathways [eqn. (8)]…”