Linked Life Data

10936615

Source:http://linkedlifedata.com/resource/pubmed/id/10936615

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2000-10-5
pubmed:abstractText
As a reference compound library for the investigation of biosynthesis of brassinosteroids, focused on a pathway from campesterol (1) to campestanol (2), 6-oxy functionalized campest-4-en-3-ones as well as campest-5-en-3-one (7) and campestane-3,6-dione were prepared from 1. Oxidation of 1 with pyridinium chlorochromate buffered by calcium carbonate gave 5-en-3-one (7) in 76% yield. Treatment of 7 with silica gel under an oxygen atmosphere in ethyl ether at room temperature produced efficient hydroperoxidation at the C-6 position to give 6alpha-hydroperoxycampest-4-en-3-one and 6beta-hydroperoxycampest-4-en-3-one in 34% and 49% yields, respectively. These compounds were converted to 6alpha-hydroxycampest-4-en-3-one and 6beta-hydroxycampest-4-en-3-one by reduction with triethyl phosphite. This provided the first example of the practical use of hydroperoxidation at C-6 of a Delta(5(6))-unsaturated 3-oxo-steroid with molecular oxygen and silica gel. On the other hand, oxidation of 1 with pyridinium chlorochromate in the absence of calcium carbonate gave campest-4-ene-3,6-dione in 64% yield. This compound was then converted in a highly stereoselective manner to campestane-3,6-dione with A/B trans ring junction by reduction with titanium (III) chloride in 85% yield.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0039-128X
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
443-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Synthesis of 6-oxy functionalized campest-4-en-3-ones: efficient hydroperoxidation at C-6 of campest-5-en-3-one with molecular oxygen and silica gel.
pubmed:affiliation
The Institute of Physical and Chemical Research (RIKEN), Wako-shi, 351-0198, Saitama, Japan. hseto@postman.riken.go.jp
pubmed:publicationType
Journal Article