Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377681
Title: The total synthesis of linear anthrasteroids
Author: Davison, Peter R.
Awarding Body: Sheffield City Polytechnic
Current Institution: Sheffield Hallam University
Date of Award: 1987
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Abstract:
The aim of the project was to synthesize linear anthrasteroid analogues of testosterone, 19-nortestosterone and estradiol. A total synthesis of (+/-)-7,11-cyclo-8,9-seco-19-nor-testosterone, (+/-)-7,11-cyclo-8,9-secoestradiol and (+/-)-1beta-t-butoxy-9a,11abeta-dimethyl-1,2,3, 3aalpha, 4, 4aalpha, 5,8,9, 9a,10,10alphabeta,11,11a-tetradecahydro-7-cyclopent[b]anthrac-enone was accomplished. The synthesis presented provides a short, direct route to linear anthrasteroid analogues. This compares favourably with the synthesis reported by S. Aoyama and K. Sasaki, which involves complex transformations of steroids. The synthetic route involved the synthesis of the trans-bicyclic hydrindan, (+/-)-1beta-t-butoxy-7abeta-methyl-3aalpha,4,7,7a-tetrahydro-5(6H)-indanone, using the synthetic pathway developed by Z.G. Hajos and D.R. Parrish. This intermediate was regiospecifically annulated to give the novel tricyclic enone, (+/-)-1beta-t-butoxy-9abeta-methyl-l,2,3,3aalpha,4,7,8,8abeta,9,9a-decahydro-6-benz[f]indenone via two different routes. Thestereochemistry of the new ring junction was elucidated by using H n.m.r. spectroscopy and the lanthanide shift reagent Eu(FOD)[3].Further regiospecific annulation of the tricyclic enone gave the novel linear tetracyclic compound, (+/-)-1beta-t-butoxy-lla-methyl-1,2,3,3abeta,4,4abeta,5,8,9,9abeta,10,10abeta,11,11a-tetradecahydro-7-cyclopent[b]anthracenone. The t-butyl group of this compound was removed to give (+/-)-7,11-cyclo-8,9-seco-19-nortestosterone, or the A-ring was aromatized and the t-butyl group cleaved to give (+/-)-7,11-cyclo-8,9-seco estradiol. The synthesis of linear anthrasteroid analogues of testosterone was accomplished by regiospecific methylation of the tricyclic enone to give the novel compound (+/-)-1betat-butoxy-7,9abeta-dimethyl-1,2,3,3a?,4,7,8,8abeta,9,9a-decahydro-6-benz[f]indenone. Regiospecific annulation of this compound gave a mixture of stereoisomers,(+/-)-1beta-t-butoxy-9abeta,11aB-dimethyl-1,2,3,3abeta,4,4a,5,8,9,9a,10,10abeta, 11, 11a-tetradecahydro-7-cyclopent[b]anthracenone and (+/-)-1beta-t-butoxy-9ad, 11abeta-di-methy 1-1,2,3,3aA, 4,4aA, 5,8,9,9a,10,10abeta,11, 11a-tetra-decahydro-7-cyclopent[b]anthracenone.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.377681  DOI: Not available
Keywords: Anthrasteroid analogues
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