cad a22 4500 316949558 20181103043304.0 cr unu---uuuuu 140620s1985 xx s 000 0 ger 10.5167/uzh-96603 doi 10.1002/hlca.19850680210 doi (ZORA)oai:www.zora.uzh.ch:96603 540 ddc Lukac Josef Umlagerungsreaktionen von (2'-Propinyl)cyclohexadienolen und -semibenzolen [Elektronische Daten] [Josef Lukac, Heinz Heimgartner] closedAccess eu-repo The acid-catalyzed dienol-benzene rearrangement of 3- and 5-methyl-substituted (2'-propiny1)cyclohexadienols has been investigated. Treatment of the dienols with CF3COOH in CCl4 yields allenyl- and (2'-propiny1)benzenes via [3,4]- and [1,2]-sigmatropic rearrangements, respectively. The reaction with H2SO4 in Et2O leeds to a mixture of allenyl-, 2'-propinyl-, 3'-butinyl- and (2',3'-butadienyl)benzenes (Scheme 3). The latter are products of a thermal semibenzene-benzene rearrangement (cf: Scheme 9). The corresponding semibenzenes have been prepared by dehydration of the cyclohexadienols with H2SO4 or POCl3 (Schemes 6 and 7). Under acidic conditions, the p-(2'-propinyl)semibenzenes 33-35 (Scheme 8) undergo [3,4]- and [1,2]-slgmatropic rearrangements to give again allenyl- and (2'-propinyl)benzenes, whereas the thermal rearrangements to the 3‘-butinyl- and (2',3'-butadienyl)benzenes (Scheme 9) involves a radical mechanism. Incontrast, the o-(2'-propiny1)semibenzene b (Scheme 7) leads to (2',3‘-butadieny1)benzene 32 via a thermal [3,3]-sigmatropic rearrangement. Department of Chemistry zora Physical and Theoretical Chemistry, Inorganic Chemistry, Organic Chemistry, Biochemistry, Drug Discovery, Catalysis zora Heimgartner Heinz joint author Helvetica Chimica Acta 68(2):355-370 https://www.zora.uzh.ch/id/eprint/96603/1/91_Lukac_HCA_1985.pdf text/html WWW-Backlink auf das Repository 1 Journal Article PeerReviewed zora ZORA 856 40 https://www.zora.uzh.ch/id/eprint/96603/1/91_Lukac_HCA_1985.pdf text/html WWW-Backlink auf das Repository ZORA 100 1- Lukac Josef ZORA 700 1- Heimgartner Heinz joint author ZORA 773 0- Helvetica Chimica Acta 68(2):355-370 BK010053 XK010053 XK010000 ZORA ZORA ZORA Journal Article closedAccess