The Steric Course of Nitrosyl Halide Additions to Norbornene and Norbornadiene

The reactions of nitrosyl chloride and dinitrogen tetroxide with acetylated glycals. Acetylated 2-deoxy-2-nitroso-α-D-hexopyranosyl chlorides and nitrates and acetylated 2-nitroglycals

“…Although nitrosyl chloride has been used extensively since its early introduction into organic chemistry (I), the mechanism and stereochemical route of the addition of nitrosyl chloride to olefinic double bonds has received attention only in recent years (2,3). The kinetic studies by Beier and co-workers (2) led to the conclusion that the reaction proceeds by way of a moderately polar and highly ordered transition state.…”

“…The kinetic studies by Beier and co-workers (2) led to the conclusion that the reaction proceeds by way of a moderately polar and highly ordered transition state. Meinwald, Meinwald, and Baker (3) concluded that the cis-addition to strained olefins involves a four-centered addition mechanism. Although no reference could be found to addition of nitrosyl chloride to vinyl ethers, it could be anticipated at the debut of this investigation that nitrosyl chloride would add readily to acetylated glycals in a cis-addition as previously noted for the chlorination of the triacetates of D-glucal and D-galactal (4).…”

The Stereochemistry of Electrophilic Additions to Olefins and Acetylenes

“…Somewhat more is known about the stereochemistry of nitrosyl halide additions to bicyclic systems, mainly from the studies of Meinwald and co-workers (345). They find that nitrosyl chloride and nitrosyl bromide add to norbornene to give 65 and 807,, respectively, of the cis-exo adduct (235) isolated as the dimer.…”

Nitrosyl Chloride

“…10 With some bicyclic systems (including norbornene and norbornadiene), there is evidence of syn addition via a four-center transition state. 11 Generally good yields for this reaction can be obtained by using NaNO 2 and HCl.…”