Stereoselectivity of the Hydration of Representative Cyclic and Bicyclic Olefins by the New Oxymercuration-Demercuration Procedure

Biologically active polycycloalkanes. 2. Antiviral 4-homoisotwistane derivatives

“…(C12H20O) C, H. 4-Homoisotwist-3-ylcarbonyl Chloride (15). To a solution of 5.5 g (0.028 mol) of 4-homoisotwistane-3-carboxylic acid (12) in 20 ml of benzene was dropped at ambient temperature with stirring 12 ml of thionyl chloride and the mixture was stirred under reflux for 1 h. After most of the benzene and the excess thionyl chloride had been distilled off, the residue was fractionated to give 5.4 g (90% yield) of 15: colorless liquid; bp 96-97°(0.9 mm); n22D 1.5238; ir (neat) 2930, 2860,1790,1470,1450, 990, 920, 880, 750, 650 cm*1; NMR (CCU) 1.2-2.4 (complex m); mass spectrum m/e (rel intensity) 194 ( 23), 150 (12), 149 (100), 93 (14), 91 (15), 81 (22), 79 (21), 67 (36), 41 (21), 39 (14), 28 (15). Anal.…”

“…Dry hydrogen chloride was bubbled into this ether solution to precipitate 1.1 g (68% yield) of the hydrochloride (21) of 17, which was purified by recrystallization from methanol-acetone: mp 255-260°dec (sealed tube); ir (Nujol) 1600, 1500 cm*1; mass spectrum m/e (rel intensity) 179 (16), 149 (77), 93 (16), 81 (33), 79 (19), 67 (51), 41 (19), 30 (49), 18 (100), 17 (22). Anal.…”

ChemInform Abstract: PREPARATION OF TRANS‐5‐HYDROXY‐L‐PIPECOLIC ACID AND CIS‐4‐HYDROXY‐L‐PIPECOLIC ACID FROM L‐BAIKIAIN (1,2,5,6‐L‐TETRAHYDROPYRIDINE‐2‐CARBOXYLIC ACID)

“…The oxymercuration-demercuration is a synthetically useful reaction, particularly so since Brown et al ( 6 ) proposed a simplified recipe. The exact reaction course however, is still a matter of debate ( 7 ) .…”

Oxymercuration-demercuration and hydroboration-oxidation of endo-tricyclo[5.2.2.02,6]undeca-3,8-diene. Stereospecific oxymercuration leading to the 4-exo-hydroxy derivative

“…The slow formation of 10 then could be attributed to a high activation energy associated with cis addition,28 while an unusually low trans addition rate for the formation of 11 might be a result of steric hindrance to the approach of the nucleophile from endo side. An exo cis addition mechanism also in the oxymercuration of 13 (Scheme III) is indicated by its low reactivity (33% completion in 24 hr) and exclusive formation of the exo products (14 and 15), especially that of the exo acetate23,24 15. Contrary to the monoolefins 9 and 13, the diene 1 shows high reactivity and selectivity in oxymercuration.…”

“…Oxymercuration of endo-tricyclo[5.2.2.02,6]undec-8-ene (13), prepared either by partial hydrogenation of the diene 1 in the presence of Wilkinson complex [(PPhslsRhCl]19 (Scheme III) or by Diels-Alder addition of cyclohexa-1,3diene and cyclopentene, proceeded also fairly slowly, 33% of the reactant 13 having disappeared in 24 hr at ambient temperature. The products were 71% 8-exo-hydroxy-endotricyclo[5.2.2.02,6]undecane ( 14) and 29% of its acetate (15) (Scheme III). The structures of 14 and 15 were unambiguously established by comparison of VPC retention time and mass spectrum with those of authentic specimens prepared by hydroboration-oxidation of the olefin 13 and subsequent acetylation, as described below (Scheme IV).…”