Synthesis of (+)(S)-3-Methyl-1-pentene

Abstract

Methyl-l-pentene (i.e., L-3-methyl-l-pentene) having an optical purity of at least 86% has been prepared in five steps starting from (-)(S)-2-methyl-l-butanol with an over-all yield of 18% and a maximum per cent of racemization of 12.6%. The optical purity of the ( + )(S)-3-methyl-l-pentene was calculated by regenerating the (+ XS)-3-methy 1-1-pentanol by addition of the olefin to diisobutylaluminum monohydride and by oxidation followed by hydrolysis of the trialkylaluminum thus obtained.

13C-Enriched End Groups of Poly(3-methyl-1-pentene) Prepared in the Presence of Metallocene Catalysts

“…8 (S)-3MP1 was synthesized according to the literature. 9 (R,S)-3MP1 (Fluka) was distilled on Al(iBu)3. Toluene was refluxed 48 h over sodium before use.…”

Silylformylation of Chiral 1-Alkynes, Catalysed by Solvated Rhodium Atoms

“…Synthesis of (S)-3-Methyl-1-pentene (4a): [29] H 2 O 2 (30%, 130 mL) was slowly added to (S)-N,N-dimethyl-3-methylpentylamine {54 g, 0.42 mol; [α] D 25 ϭ ϩ11.62 (l ϭ 1)} according to the procedure reported by Cram. [48] The reaction mixture was stirred for 15 h at room temperature until a clear solution resulted.…”

“…NMR (50.3 MHz, CDCl 3 , 25°C): δ ϭ 11.2 (CH 3 ),19.2 (CH 3 ),29.2 (CH), 31.7 (CH 2 ), 41.3 (CH 2 ), 180.3(CO).Synthesis of (S)-N,N-Dimethyl-3-methylpentanamide (10):SOCl 2 (83 mL, 1.14 mol) was slowly added, at Ϫ10°C under nitrogen, to a solution of (S)-3-methylpentanoic acid (66 g, 0.57 mol; [α] D 25 ϭ ϩ8.47) in 225 mL of diethyl ether. The solution was refluxed for 5 h and the solvent and the excess SOCl 2 were distilled off.…”

Rate constants and activation energies for reaction of benzyl cation with ethers in solution: initial step in carbocationic polymerization

“…18 Interpretations of these results indicate that the reaction mechanism is more complex than the corresponding reaction mechanism for the benzyl cation. 18 Interpretations of these results indicate that the reaction mechanism is more complex than the corresponding reaction mechanism for the benzyl cation.…”