Preparation of sterically hindered geometric isomers of 7-cis-β-ionyl and β-ionylidene derivatives in the vitamin A series

Vaidhyanathan Ramamurthy, G. Tustin, C. C. Yau, R. S H Liu

Research output: Contribution to journalArticle

57 Citations (Scopus)

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 languageEnglish
Pages (from-to)193-199
Number of pages7
JournalTetrahedron
Volume31
Issue number3
DOIs
StatePublished - Jan 1 1975
Externally publishedYes

Fingerprint

Cyclohexenes
Nitriles
Acetaldehyde
Alkenes
Cyclization
Ketones
Vitamin A
Isomers
Derivatives
Temperature
Isomerization

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

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 journalArticle

@article{b8b8e7b75ea545d2bb32486dc0f7b348,
title = "Preparation of sterically hindered geometric isomers of 7-cis-β-ionyl and β-ionylidene derivatives in the vitamin A series",
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.",
author = "Vaidhyanathan Ramamurthy and G. Tustin and Yau, {C. C.} and Liu, {R. S H}",
year = "1975",
month = "1",
day = "1",
doi = "10.1016/0040-4020(75)85065-4",
language = "English",
volume = "31",
pages = "193--199",
journal = "Tetrahedron",
issn = "0040-4020",
publisher = "Elsevier Limited",
number = "3",

}

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 -