http://researchspace.auckland.ac.nz ResearchSpace@Auckland
Copyright Statement
The digital copy of this thesis is protected by the Copyright Act 1994 (New Zealand).
This thesis may be consulted by you, provided you comply with the provisions of the Act and the following conditions of use:
• Any use you make of these documents or images must be for research or private study purposes only, and you may not make them available to any other person.
• Authors control the copyright of their thesis. You will recognise the author's right to be identified as the author of this thesis, and due acknowledgement will be made to the author where appropriate.
• You will obtain the author's permission before publishing any material from their thesis.
To request permissions please use the Feedback form on our webpage.
http://researchspace.auckland.ac.nz/feedback
General copyright and disclaimer
In addition to the above conditions, authors give their consent for the digital copy of their work to be used subject to the conditions specified on the Library Thesis Consent Form.
ABSTRACT
This thesis i s c o n c r r n e d with t h e ! r t i . l i s a t i o n o f t h e n l t u r a l ;.rcc!uct, 31); e t a - 8 , i ? ,13-trim-18-oic a c i d
*
(dehydro-abictic a c i d ) ( 1 ) f o r t h e s y n t h e s i s of ontically active steroids and d i t e r ? e r ~ o i d s . The work h a s been d i v i d e d into three sections w h i c h describe transformations of r i n g s A , B , and C o f abieta-8, 11,13-trien-18-oic acid ( 1
).
S e l e c t i v e epoxidation of the alkene mixture ( 3
-
5 )derived from oxidative decarboxylation of abieta-8,11,13-trien-18- o i c acid ( 1 ) w i t h lead tetraacetate has g i v e n t h e epoxidej ( 6 4 ) , ( 6 5 1 , a l o w y i e l d of t h e epoxidp ( 6 6 ) . and t h e pure exocyclic al-kene ( 3 ) . T h e a l k e n e (3) was oxidised to t h e k e t o n e ( 6 ) vhich h a s been previously enployed as an i n t e r m e d i a t e for t h e synthesis of t h e a$-unsaturated k e t o n e (10). The epoxides (64) and ( 6 5 ) have been converted to the unsaturated ketones ( 8 9 ) , ( 1 0 7 ) , and (67), and t h e saturated k e t o n e s ( l j ) , ( 9 9 ) and (100). A s t u d y of the boron trifluoride rearrangements of t h e t h r e e epoxides ( 6 4 ) , ( 6 5 ) and ( 6 6 )
*
T h e numbering system used throughout t h i s thesis is t h a t proposed by J. W. Rowe (personal comunication to Professor 8. C. ~ a m b i e ) i n T h e Common and Systematic Nomenclature of Cyclic Diterpenesw 3rd r e v i s i o n , O c t , 1968, t o be submitted to t h e XIPAC Commission on Organic Nomenclature,ii.
h a s been : ~ a d e u s i n g benzene a n d dimethyl s u i ? h c x i d e a s s o l v e n t s , and o a t h x a y s f'or t h ~ fornation of t h e D ~ O ~ ' , L I C ~ S are suggested.
T e r a c i d oxidation of t h e en01 a c e t a t e (155) derived from
t h e C 7-ketone (18) provided a facile i n t r o c h c t i o n of oxygen s u b s t i t u e n t s into t h e hindered C 6 yosition of abieta-8,1!,73- t r i m - ~ 8 - o i c a c i d ( 1 ) . By hydrogrnolysis o f t h e C 7-hydroxy substituent of the c o ~ p o u n d ( 1 6 2 ) ~ the C & a c e t a t e (172) was o k t a i ~ e d . H y d r o l y s i s of the l a t t e r compound, and methylation of the a c i d formed gave the C 6-alcohol (17 5 ) v h i c h was oxidised to t h e C 6 - ~ e t o n e (176).
The literature pertaining to the intramolecul,-ir
f u n c t i o n a l i s a t i o n o f aromatic alkyi g r o u p s h a s been surveyed, and, with t h e ultimate a i n of s y n t h e s i z i n g the a r o r n l t i c steroids ( 2 3 7 )
and ( 2 4 9 ) , t h e C 13-isopropyl group of abieta-8,11-? 3-trim-1 8-oic
acid ( 1 ) has been f ' u n c t i o n a l i s e d by the a p p l i c a t i o n of two of t h e published p r o c e d u r e s , viz. the l e a d tetraacetate oxidation of aromatic acids, and t h e thermolysis of diazomethyl ketones.
N i t r a t i o n of methyl 12-acetylabieta-8,11,1 3-trien-I 8-oate
( 2 2 7 ) h a s given products of ~ i t r o d e a c y l a t i o n (44) and nitrodealkylation (266). The product of nitrodealkylation (266) has been converted
to me thy1 1 3-hydroxy-podocarpa-8.17,
l3-trien-l tl-oate (
59) i n 36%y i e l d . Methylation of t h e phenol ( 5 9 ) , and Birch
reduction
of the methyl ether (276) has given podocarp-8( 14)-en-78-01-1 3-one( 2 P : )
