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Volumn 19, Issue 19, 2017, Pages 5150-5153

Synthetic study toward total synthesis of (±)-germine: Synthesis of (±)-4-methylenegermine

Author keywords

[No Author keywords available]

Indexed keywords

ACETIC ACID; CEVANE DERIVATIVE; GERMINE;

EID: 85032617729     PISSN: 15237060     EISSN: 15237052     Source Type: Journal    
DOI: 10.1021/acs.orglett.7b02434     Document Type: Article
Times cited : (18)

References (35)
  • 7
    • 85032626828 scopus 로고    scopus 로고
    • The equilibrium between hemiketal=hydroxy ketone reduced the number of asymmetric centers to 15 in (+)-germine. Our interest was in the synthesis of the (±)-germine derivative rather than the (+)-isomer, reducing the relative asymmetric center from 15 to 14
    • The equilibrium between hemiketal=hydroxy ketone reduced the number of asymmetric centers to 15 in (+)-germine. Our interest was in the synthesis of the (±)-germine derivative rather than the (+)-isomer, reducing the relative asymmetric center from 15 to 14.
  • 10
    • 0016030007 scopus 로고
    • Compound 4 was previously observed in the mixture of products from the degradation of abietic acid: Wirthlin, T.; Wehrli, H.; Jeger, O. Helv. Chim. Acta 1974, 57, 351.
    • (1974) Helv. Chim. Acta , vol.57 , pp. 351
    • Wirthlin, T.1    Wehrli, H.2    Jeger, O.3
  • 11
    • 85032636728 scopus 로고    scopus 로고
    • Epoxidation from the α-face of the olefin in 4 is favored due to a steric hindrance from the angular methyl group at the C10, blocking the β-face (more than a steric hindrance from the C6 methylene group on the α-face of the olefin)
    • Epoxidation from the α-face of the olefin in 4 is favored due to a steric hindrance from the angular methyl group at the C10, blocking the β-face (more than a steric hindrance from the C6 methylene group on the α-face of the olefin).
  • 12
    • 85032631745 scopus 로고    scopus 로고
    • Treatment with either lithium diethylamide in THF or aluminum tert-butoxide in refluxing toluene, undesired α-expoxide 5α can be opened to give the undesired α-allylic alcohol (an epimer of 6). Further treatment of the undesired α-allylic alcohol with Al(iPrO) 3 (m-xylene, 135 °C) equilibrates to the desired more stable β-allylic alcohol 6 (1:4 = α/β). Further heating did not alter the ratio. Thus, a mixture of 5α and 5β was treated directly with Al(iPrO)3 in boiling m-xylene
    • Treatment with either lithium diethylamide in THF or aluminum tert-butoxide in refluxing toluene, undesired α-expoxide 5α can be opened to give the undesired α-allylic alcohol (an epimer of 6). Further treatment of the undesired α-allylic alcohol with Al(iPrO)3 (m-xylene, 135 °C) equilibrates to the desired more stable β-allylic alcohol 6 (1:4 = α/β). Further heating did not alter the ratio. Thus, a mixture of 5α and 5β was treated directly with Al(iPrO)3 in boiling m-xylene.
  • 23
    • 85032646037 scopus 로고    scopus 로고
    • We also made 21 by a different route: sodium borohydride, then benzoyl chloride on the aldehyde 20, in which the ring A glycol had been deprotected and transformed into a mono-p-methoxybenzyl ether. See the SI for the conversion of 20 to 21
    • We also made 21 by a different route: sodium borohydride, then benzoyl chloride on the aldehyde 20, in which the ring A glycol had been deprotected and transformed into a mono-p-methoxybenzyl ether. See the SI for the conversion of 20 to 21.
  • 25
    • 0001074970 scopus 로고
    • This paper is perhaps the most relevant: it makes conjugated alkoxydienes via triphenylphosphoranes and obtains the dienes in an E/Z ratio of 2.5: 1
    • (b) Mandai, T.; Osaka, K.; Kawagishi, M.; Kawada, M.; Otera, J. J. Org. Chem. 1984, 49, 3595. This paper is perhaps the most relevant: it makes conjugated alkoxydienes via triphenylphosphoranes and obtains the dienes in an E/Z ratio of 2.5:1.
    • (1984) J. Org. Chem , vol.49 , pp. 3595
    • Mandai, T.1    Osaka, K.2    Kawagishi, M.3    Kawada, M.4    Otera, J.5
  • 27
  • 30
    • 0025364121 scopus 로고
    • We made this compound, originally, by ozonolysis of the bis TBS derivative of cis 1, 4-butenediol
    • (b) Aszodi, J.; Bonnet, A.; Teutsch, G. Tetrahedron 1990, 46, 1579. We made this compound, originally, by ozonolysis of the bis TBS derivative of cis 1, 4-butenediol.
    • (1990) Tetrahedron , vol.46 , pp. 1579
    • Aszodi, J.1    Bonnet, A.2    Teutsch, G.3
  • 32
    • 85032636368 scopus 로고    scopus 로고
    • The stereochemistry of 27b was confirmed by X-ray analysis of the derivative 35. See the SI for the conversion of 27b to 35
    • The stereochemistry of 27b was confirmed by X-ray analysis of the derivative 35. See the SI for the conversion of 27b to 35.
  • 35
    • 0032508065 scopus 로고    scopus 로고
    • A plan for conversion of 33a to 1 was (with various deprotections/protections) C4-CH2OH to C4-CO2H, followed by Barton's conditions to change C4-CO2H to C4-OH. Barton, D. H. R.; Gero, S. D.; Holliday, P.; Quiclet-Sire, B.; Zard, S. Z. Tetrahedron 1998, 54, 6751.
    • (1998) Tetrahedron , vol.54 , pp. 6751
    • Barton, D.H.R.1    Gero, S.D.2    Holliday, P.3    Quiclet-Sire, B.4    Zard, S.Z.5


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.