%0 Generic %A Lan, Ping %A Banwell, Martin G. %A Willis, Anthony C. %D 2019 %T Application of Electrocyclic Ring-Opening and Desymmetrizing Nucleophilic Trappings of meso-6,6-Dibromobicyclo[3.1.0]hexanes to Total Syntheses of Crinine and Haemanthamine Alkaloids %U https://acs.figshare.com/articles/dataset/Application_of_Electrocyclic_Ring-Opening_and_Desymmetrizing_Nucleophilic_Trappings_of_i_meso_i_-6_6-Dibromobicyclo_3_1_0_hexanes_to_Total_Syntheses_of_Crinine_and_Haemanthamine_Alkaloids/7794164 %R 10.1021/acs.joc.9b00018.s005 %2 https://ndownloader.figshare.com/files/14505140 %K alkaloids %K application %K ent %K mixture %K -2-bromo %K Electrocyclic Ring-Opening %K pretazettine %K Total Syntheses %K Haemanthamine Alkaloids %K Suzuki %K diastereoisomeric %K hydroxyvattitine %K Desymmetrizing Nucleophilic Trappings %K Variations %K chiral %K chromatographically %K presence %K Crinine %K tazettine %K apohaemanthamine %K 1- %K C 2 %K cross-coupling %K haemanthamine %K dibromobicyclo %K hamayne %K cyclization %K Pictet %K nonracemic %K electrocyclic ring-opening %K bulbispermine %K crinane %K synthese %K meso %K 13 steps %K Dibromobicyclo %X The thermally induced electrocyclic ring-opening of C2-symmetric (meso) 6,6-dibromobicyclo[3.1.0]­hexanes such as 10 in the presence of the chiral, nonracemic 1°-amine 28 afforded a ca. 1:1 mixture of the diastereoisomeric and chromatographically separable 1-amino-2-bromo-2-cyclohexenes 37 (42%) and 38 (45%). Each of these was elaborated over 13 steps, including Suzuki–Miyaura cross-coupling, radical cyclization, and Pictet–Spengler reactions, into (−)- or (+)-crinane (1 or ent-1, respectively). Variations on these protocols were applied to the total syntheses of (+)- and (−)-11-hydroxyvattitine [(+)- and (−)-3], (+)- and (−)-bulbispermine [(+)- and (−)-4], (+)- and (−)-haemanthamine [(+)- and (−)-5], (+)- and (−)-pretazettine [(+)- and (−)-6], and (+)- and (−)-tazettine [(+)- and (−)-7] as well as (±)-hamayne [(±)-8] and (±)-apohaemanthamine [(±)-9]. A number of these alkaloids were synthesized for the first time. %I ACS Publications