Chem. J. Chinese Universities ›› 2015, Vol. 36 ›› Issue (3): 489.doi: 10.7503/cjcu20140798

• Organic Chemistry • Previous Articles     Next Articles

Reduction Selectivity of 2-Substituted Cyclododecanone and Conformation Analysis of trans-1,2-Disubstituted Cyclododecanes

YANG Mingyan, ZHANG Li, WANG Daoquan, WANG Ming'an*()   

  1. Department of Applied Chemistry, China Agricultural University, Beijing 100193, China
  • Received:2014-09-03 Online:2015-03-10 Published:2015-01-30
  • Contact: WANG Ming'an E-mail:wangma@cau.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21172254)

Abstract:

To confirm the cis-selectivity on the reduction of 2-substituted cyclododecanone and analyze the preferred conformation of trans-1,2-disubstituted cyclododecanes, the reduction of 2-phenyl/cyclohexylcyclododecanones were carried out at the different reductive reagents and temperatures. Based on these results, a series of trans-1,2-disub- stituted cyclododecanes was prepared via NaBH4 reduction of 2-substituted cyclodode- canones, ring-opening of cyclododecene oxide, Mitsunobu reaction of cis-2-phenyl cyclododecanol and hydrolysis, their preferred conformation were analyzed on the basis of 1H NMR, 13C NMR, X-ray diffraction and quantum chemistry calculation. The results showed that the preferred conformations of trans-1,2-disubstituted cyclododecanes were [3333] square conformation, in which the one group presents at the side-exo position and the other one at the corner-anti. The X-ray diffraction structures of the reductive products of cis-2,12-disubstituted cyclododecanones showed that 1,2,3-trisubstituted cyclodode- canes still take [3333] square conformation, in which the two groups present at the side-exo positions and the hydroxy at the corner-syn, three groups are cis-cis relationships.

Key words: 2-Phenyl/cyclohexylcyclododecanone, trans-1,2-Disubstituted cyclododecane, 1,2,3-Trisubstituted cyclododecane, Conformation analysis

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