Rearrangement studies with 14C—XIII

REARRANGEMENT STUDIES WITH C14: XIV. THE REACTION OF 2-p-ANISYLETHANOL-1-C14 WITH THIONYL CHLORIDE

“…(12,13). Exclusive SN2 reaction would lead to no rearrangement as was noted in the decomposition of 2-butyl-1-C14 chlorosulphite in pyridine (8). For the present system, the 0.4-0.5% rearrangement observed in pyridine is beyond experimental error, indicating some contribution from VII even in pyridine.…”

“…rearrangement observed (8). In the 2-p-anisylethyl-1-C14 system, the rearrangement obtained for reaction in dioxane is almost as large as that found in the reaction in excess thionyl chloride (Table I).…”

“…A subsequent displacement of the dioxane by chloride ion would lead t o overall retention (1). Relatively low degrees of rearrangement, attributable to the special solvent effect of dioxane, were reported for the decomposition in dioxane of allyl-l-Cl4 chlorosulphite (4) and of 2-butyl-1-CL4 chlorosulphite (8). In the case of the 2-butyl-l-Cl4 system, the relative inability of neighboring hydrogen to participate and displace dioxane from the solvated cation was suggested as a possible explanation.…”

“…Since the suggestion that the decomposition of the chlorosulphite has considerable Ionic character (2), and that the SNi reaction is quite similar to the S N l reaction in that both involve ion pairs (3), a number of studies on the ionic nature of this reaction have been reported (1,(4)(5)(6)(7)(8). Among these were investigations on isotope position rearrangements in the thermal decomposition, in a number of solvents, of allyl-1-Cl" chlorosulphite (4) and of 2-butyl-1-C14 chlorosulphite (8). The present paper reports the extents of rearrangement of the C14 label, and discusses the mechanistic implications of these re-arrangements, in the reaction between 2-P-anisylethanol-1-C14 and thionyl chloride, with pyridine, n-hexane, toluene, dioxane, or excess thionyl chloride as solvent.…”

Isotopic Scrambling and Mass Spectral Fragmentation Studies with 2-Ferrocenylethyl and 2-Ferrocenylethyl-1,1-D2 Systems

“…While the treatment of 1-OH-1-d, with excess SOCI, resulted in extensive decomposition, 1-C1-1-d, was prepared without rearrangement from the reaction of 1-OH-1-d2 with SOCI, in tetrahydrofuran or toluene as solvent. The observation that 1-C1-1-d2 was formed without any isotopic scrambling is also of interest since, for example, the reaction of 2-phenylethanol-1-14C with SOCI, without a solvent gave essentially a complete scrambling of the label between C-1 and C-2 (6), while degenerate rearrangements arising from 1,2-hydride shifts were observed even in a nonpolar solvent such as toluene when 2-butyl chloride was formed from the decomposition of 2-butyl-1-14C chlorosulfite derived from the alcohol and SOCI, (7). When 1-C1-1-d, was treated with AlCl, in CH2C12, the recovered 1-C1-1-d2 was again isotopically nonrearranged.…”