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Stereospecific Syntheses from Podocarpic Acid

by Fullerton, T. J.

Abstract (Summary)
The triterpene precursor, 12-methoxypodocarpa-8,11,13-trien-3-one (46)*, has been prepared via the 3a-alcohol (48) formed by opening of the 3a,4a-epoxide (13) with lithium diethylamide. The total synthesis of the methyl ether of the natural product, (+)-hinokione, has been achieved by a similar sequence involving prior addition of an isopropyl group at C 13 of the methoxy acid (4) ( Scheme 1 ) . A study of the boron trifluoride rearrangements of the three epoxides (12), (13), and (14), has been made using benzene and dimethyl sulphoxide as solvents. The stereochemistry of a series of 6-bromo-7-oxo derivatives of diterpenoids possessing an aromatic ring-C is discussed and the assignment of configuration of the 6-bromo substituents from n.m.r. and n.0.e. data is examined. A preliminary investigation into the possibility of preparing a 9a-methyl steroidal analogue by addition of a cyclopentatone ring across positions 3 and 4 of ring-A of the podocarpic system is also reported.
Bibliographical Information:

Advisor:Drs J.M. Coxon and M.P. Hartshorn

School:The University of Auckland / Te Whare Wananga o Tamaki Makaurau

School Location:New Zealand

Source Type:Master's Thesis

Keywords:fields of research 250000 chemical sciences

ISBN:

Date of Publication:01/01/1971

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