Abstract
The preparation of the relatively unknown 7-cis isomers of β-ionyl and β-ionylidene derivatives via one way sensitized geometric isomerization is described. These highly sterically crowded isomers, once prepared do not readily thermally revert back to the trans. But the trienes, at temperatures ≥ 100° undergo irreversible cyclization to cyclohexadienes. 7-cis Isomers of β-ionylideneacetone and acetaldehyde as well as higher tetraenes and pentaenes in this series could not be prepared by sensitized isomerization. Partial reduction of 7-cis-β-ionylideneacetonitrile isomers led to the preparation of 7-cis- and 7,9-dicis-β-ionylideneacetaldehyde; and methyl Grignard reaction with the same nitrile gave the triene-methyl ketones.
| Original language | English |
|---|---|
| Pages (from-to) | 193-199 |
| Number of pages | 7 |
| Journal | Tetrahedron |
| Volume | 31 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 1 1975 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
- Organic Chemistry
- Drug Discovery
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Preparation of sterically hindered geometric isomers of 7-cis-β-ionyl and β-ionylidene derivatives in the vitamin A series. / Ramamurthy, Vaidhyanathan; Tustin, G.; Yau, C. C.; Liu, R. S H.
In: Tetrahedron, Vol. 31, No. 3, 01.01.1975, p. 193-199.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Preparation of sterically hindered geometric isomers of 7-cis-β-ionyl and β-ionylidene derivatives in the vitamin A series
AU - Ramamurthy, Vaidhyanathan
AU - Tustin, G.
AU - Yau, C. C.
AU - Liu, R. S H
PY - 1975/1/1
Y1 - 1975/1/1
N2 - The preparation of the relatively unknown 7-cis isomers of β-ionyl and β-ionylidene derivatives via one way sensitized geometric isomerization is described. These highly sterically crowded isomers, once prepared do not readily thermally revert back to the trans. But the trienes, at temperatures ≥ 100° undergo irreversible cyclization to cyclohexadienes. 7-cis Isomers of β-ionylideneacetone and acetaldehyde as well as higher tetraenes and pentaenes in this series could not be prepared by sensitized isomerization. Partial reduction of 7-cis-β-ionylideneacetonitrile isomers led to the preparation of 7-cis- and 7,9-dicis-β-ionylideneacetaldehyde; and methyl Grignard reaction with the same nitrile gave the triene-methyl ketones.
AB - The preparation of the relatively unknown 7-cis isomers of β-ionyl and β-ionylidene derivatives via one way sensitized geometric isomerization is described. These highly sterically crowded isomers, once prepared do not readily thermally revert back to the trans. But the trienes, at temperatures ≥ 100° undergo irreversible cyclization to cyclohexadienes. 7-cis Isomers of β-ionylideneacetone and acetaldehyde as well as higher tetraenes and pentaenes in this series could not be prepared by sensitized isomerization. Partial reduction of 7-cis-β-ionylideneacetonitrile isomers led to the preparation of 7-cis- and 7,9-dicis-β-ionylideneacetaldehyde; and methyl Grignard reaction with the same nitrile gave the triene-methyl ketones.
UR - http://www.scopus.com/inward/record.url?scp=0016434578&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0016434578&partnerID=8YFLogxK
U2 - 10.1016/0040-4020(75)85065-4
DO - 10.1016/0040-4020(75)85065-4
M3 - Article
AN - SCOPUS:0016434578
VL - 31
SP - 193
EP - 199
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 3
ER -