62210-83-7Relevant articles and documents
On the Absolute Stereochemistries of (-)-Benzocyclohepten-3-ol, (-)-2,3,4,5-Tetrahydro-1-benzoxepin-5-ol, and (-)-Benzocycloocten-3-ol
Kasai, Masaji,Ziffer, Herman
, p. 712 - 715 (1983)
The configurations of (-)-benzocyclohepten-3-ol (2a), (-)-2,3,4,5-tetrahydro-1-benzoxepin-5-ol (6a), and (-)-benzocycloocten-3-ol (9a), which were prepared by microbial reduction of the corresponding keto compounds by Cryptococcus macerans, were established as S by conversion to dimethyl α-acetoxy dicarboxylate esters of known configuration.The elution order of the enantiomers of each of these three carbinols and their acetates from a Pirkle chiral-phase HPLC column was not consistent with that found for the lower homologues, 1-indanol and 1-tetralol.These results indicat e great care must be exercised in the use of elution order for the determination of configurations.
Guanidine–Copper Complex Catalyzed Allylic Borylation for the Enantioconvergent Synthesis of Tertiary Cyclic Allylboronates
Ge, Yicen,Cui, Xi-Yang,Tan, Siu Min,Jiang, Huan,Ren, Jingyun,Lee, Nicholas,Lee, Richmond,Tan, Choon-Hong
supporting information, p. 2382 - 2386 (2019/02/01)
An enantioconvergent synthesis of chiral cyclic allylboronates from racemic allylic bromides was achieved by using a guanidine–copper catalyst. The allylboronates were obtained with high γ/α regioselectivities (up to 99:1) and enantioselectivities (up to 99 % ee), and could be further transformed into diverse functionalized allylic compounds without erosion of optical purity. Experimental and DFT mechanistic studies support an SN2′ borylation process catalyzed by a monodentate guanidine–copper(I) complex that proceeds through a special direct enantioconvergent transformation mechanism.
Precision vinyl acetate/ethylene (VAE) copolymers by ROMP of acetoxy-substituted cyclic alkenes
Zhang, Jihua,Matta, Megan E.,Martinez, Henry,Hillmyer, Marc A.
, p. 2535 - 2543 (2013/06/04)
Precision linear vinyl acetate/ethylene (VAE) copolymers containing acetoxy groups on precisely every eighth backbone carbon were synthesized by ring-opening metathesis polymerization (ROMP) of racemic 3-acetoxy cyclooctene (3AcCOE) followed by hydrogenation. The use of enantiomerically pure 3AcCOE resulted in an optically active polyalkenamer that afforded isotactic precision VAE materials after hydrogenation. Both of these VAE polymers are semicrystalline (by differential scanning calorimetry and wide-angle X-ray scattering) due to their high degrees of regioregularity and the isotactic VAE samples exhibited a higher apparent degree of crystallinity and melting point compared to the atactic version. In contrast, analogous linear VAE copolymers derived from ROMP-hydrogenation of racemic 4- or 5-acetoxy cyclooctenes were regio-irregular and completely amorphous. The ROMP-hydrogenation of 3-acetoxy cycloheptene also affords precision linear VAE copolymers with acetoxy groups on every seventh carbon, but this polymer was noncrystalline. Mechanical characterization showed that the precision 3AcCOE-derived VAE samples possess improved mechanical properties compared to the compositionally similar commercial VAE copolymers produced by radical copolymerization.
