ChemInform Abstract: Addition Reactions to Bicyclobutane Derivatives. Part 11. Hydromethoxylation and Methoxymercuration of Methyl 7‐Methyltricyclo(4. 1.0.02,7)heptane‐1‐carboxylate.

Abstract

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Chemo-, regio-, and stereoselectivity in acid-catalyzed hydromethoxylation of tricyclo[4.1.0.02,7]hept-1-yl and 7-methyltricyclo[4.1.0.02,7]hept-1-yl phenyl sulfones

“…The sixth component was not identified. The hydromethoxylation of compound XIV was more unambiguous: the addition of methanol involved exclusively the side C 1 -C 2 bond with formation of two diastereoisomeric norcaranes XVIIIa and XVIIIb [8]. In each couple of diastereoisomeric substituted norcaranes XVa/XVb, XVIa/XVIb, and XVIIIa/XVIIIb the isomer with endo orientation of the 2-methoxy group prevailed.…”

“…The norcarene skeleton of compounds XXI and XXII is reliably identified by the 1 H NMR spectra that resemble the spectra of model norcarenes where the SO 2 Ph group is replaced by CO 2 Me [7,8]. The exo orientation of the sulfonyl group on C 7 in both compounds XXI and XXII is consistent with the stereochemistry of opening of the side C-C bond, determined previously (the configuration at the site of electrophilic attack was conserved) and is directly confirmed by the 1 H NMR data: the coupling constant for the H α proton is equal to 5-6 Hz, which is typical of trans orientation of vicinal protons in cyclopropanes [11].…”

“…In both cases, the products were two diastereoisomeric norcarane derivatives XIXa/XIXb and XXa/XXb, respectively, which were formed via addition of methanol at the C 1 -C 2 side bicyclobutane bond contiguous to the electron-withdrawing substituent. The corresponding norcarene sulfones XXI and XXII that are isomeric to initial tricycloheptanes XI and XII were present in a small amount (4-8%); they were separated from methoxynorcaranes XIXa/XIXb and XXa/XXb by column chromatography on aluminum oxide and identified by comparison with samples obtained by isomerization of XI and XII in benzene in the presence of a catalytic amount of HClO 4 [8,9].…”