In:
Bulletin of the Chemical Society of Japan, Oxford University Press (OUP), Vol. 57, No. 3 ( 1984-03-01), p. 747-751
Abstract:
Methyl (+)-12-benzoyloxy-11,14-dioxo-8,12-abietadien-18-oate was converted into methyl 11,12,14-trimethoxy-8,11,13-abietatrien-18-oate (8). The Grignard reaction of 8 with phenylmagnesium bromide, followed by oxidation with lead tetraacetate, afforded 11,12,14-trimethoxy-19-norabieta-4(18),8,11,13-tetraene. This was then converted into 3α-bromo-11,12,14-trimethoxy-18-norabieta-8,11,13-trien-2-one (15) by a series of reactions: selenium dioxide oxidation, catalytic hydrogenation, dehydration, hydroxybromination, and Jones oxidation. Acetalization of 15 with 1,2-ethanediol, followed by oxidation with Jones reagent and then with oxygen in the presence of potassium t-butoxide, afforded 3-bromo-2,2-ethylenedioxy-6-hydroxy-11,12,14-tri-methoxy-18-norabieta-5,8,11,13-tetraen-7-one, which was converted into (−)-coleon B tri-O-methyl ether (4) by hydrolysis and dehydrobromination. Another conversion of 15 into 4 was also achieved by a series of reactions: debromination, acetalization, Collins oxidation, oxygen oxidation, hydrolysis, and dehydrogenation.
Type of Medium:
Online Resource
ISSN:
0009-2673
,
1348-0634
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
1984
detail.hit.zdb_id:
2041163-7
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