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Volumn 47, Issue 49, 2008, Pages 9450-9453

An efficient substrate-controlled approach towards hypoestoxide, a member of a family of diterpenoid natural products with an inside-out [9.3.1]bicyclic core

Author keywords

Atropisomerism; Cyclization; Hypoestoxide; Natural products; Total synthesis

Indexed keywords

ATROPISOMERISM; BICYCLIC PRODUCTS; CHEMICAL EQUATIONS; CLOSING METATHESES; DITERPENOID; HYPOESTOXIDE; NATURAL PRODUCTS; TOTAL SYNTHESIS;

EID: 56749112418     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200804237     Document Type: Article
Times cited : (21)

References (50)
  • 17
    • 0032568262 scopus 로고    scopus 로고
    • For ring-closing metathesis tethers, see: a
    • For ring-closing metathesis tethers, see: a) D. J. O'Leary, S. J. Miller, R. H. Grubbs, Tetrahedron Lett. 1998, 39, 1689-1690;
    • (1998) Tetrahedron Lett , vol.39 , pp. 1689-1690
    • O'Leary, D.J.1    Miller, S.J.2    Grubbs, R.H.3
  • 25
    • 33747884493 scopus 로고    scopus 로고
    • for an asymmetric variant of this methodology, see
    • b) for an asymmetric variant of this methodology, see: B. M. Trost, R. N. Bream, J. Xu, Angew. Chem. 2006, 118, 3181-3184;
    • (2006) Angew. Chem , vol.118 , pp. 3181-3184
    • Trost, B.M.1    Bream, R.N.2    Xu, J.3
  • 26
    • 33746191949 scopus 로고    scopus 로고
    • Angew. Chem. Int. Ed. 2006, 45, 3109-3112;
    • (2006) Angew. Chem. Int. Ed , vol.45 , pp. 3109-3112
  • 34
    • 56749145729 scopus 로고    scopus 로고
    • Successful metathesis cyclizations took place only when the Grubbs 2nd generation catalyst was used. All other metathesis catalysts gave no product.
    • Successful metathesis cyclizations took place only when the Grubbs 2nd generation catalyst was used. All other metathesis catalysts gave no product.
  • 35
    • 0038163433 scopus 로고    scopus 로고
    • The effects of titanium additives for metathesis reactions have previously been reported, but none are as dramatic as the example discussed herein. See also: a A. Fürstner, K. Langemann, J. Am. Chem. Soc. 1997, 119, 9130-9136;
    • The effects of titanium additives for metathesis reactions have previously been reported, but none are as dramatic as the example discussed herein. See also: a) A. Fürstner, K. Langemann, J. Am. Chem. Soc. 1997, 119, 9130-9136;
  • 38
    • 0001399412 scopus 로고    scopus 로고
    • Angew. Chem. Int. Ed. 2000, 39, 3012-3043.
    • (2000) Angew. Chem. Int. Ed , vol.39 , pp. 3012-3043
  • 39
    • 56749114054 scopus 로고    scopus 로고
    • Complete NMR spectroscopic analysis, including full proton and carbon assignments from HSQC and HMBC data, and stereochemical assignments from NOESY data, can be found in the Supporting Information
    • Complete NMR spectroscopic analysis, including full proton and carbon assignments from HSQC and HMBC data, and stereochemical assignments from NOESY data, can be found in the Supporting Information.
  • 41
    • 56749109322 scopus 로고    scopus 로고
    • Independently of this study, we have converted diol 28 into 22 in five steps (bisepoxidation, acetylation, dehydration, allylic oxidation, and oxidation).
    • Independently of this study, we have converted diol 28 into 22 in five steps (bisepoxidation, acetylation, dehydration, allylic oxidation, and oxidation).
  • 42
    • 56749147982 scopus 로고    scopus 로고
    • To further highlight the fine balance needed for a successful cyclization, it is worth noting that the correct C12-hydroxy isomer does not undergo ring-closing metathesis.
    • To further highlight the fine balance needed for a successful cyclization, it is worth noting that the correct C12-hydroxy isomer does not undergo ring-closing metathesis.
  • 43
    • 56749115570 scopus 로고    scopus 로고
    • The substrate-controlled reduction of the ketone can be explained by the geminal dimethyl group on the ring, which blocks the hydride delivery from what might otherwise be considered the less-hindered face
    • The substrate-controlled reduction of the ketone can be explained by the geminal dimethyl group on the ring, which blocks the hydride delivery from what might otherwise be considered the less-hindered face.
  • 47
    • 56749172189 scopus 로고    scopus 로고
    • Interestingly, the C9=C10 trisubstituted bond could be cleanly inverted to the cis epoxide using this same sequence after initially epoxidizing C5=C6. This bisepoxide was subjected to Tsuji's allylic transposition and readily underwent allylic oxidation.
    • Interestingly, the C9=C10 trisubstituted bond could be cleanly inverted to the cis epoxide using this same sequence after initially epoxidizing C5=C6. This bisepoxide was subjected to Tsuji's allylic transposition and readily underwent allylic oxidation.
  • 49
    • 56749124801 scopus 로고    scopus 로고
    • 4]/TBHP, and Pd/C/TBHP.
    • 4]/TBHP, and Pd/C/TBHP.
  • 50
    • 56749140481 scopus 로고    scopus 로고
    • All nonrigidified substrates failed to cyclize using any of the known ruthenium metathesis catalysts. Other diol diastereoisomers were also accessed and evaluated, but these also failed to cyclize
    • All nonrigidified substrates failed to cyclize using any of the known ruthenium metathesis catalysts. Other diol diastereoisomers were also accessed and evaluated, but these also failed to cyclize.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.