Medium-ring 1,5-dienes. Part III. Cyclisation of germacra-1(10),4,7-(11)-triene oxides

Brown, Elsa Barkley; Sutherland, J. K.; Sam, Teng W.

doi:10.1039/p19750002332

Cited by 17 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The thallium (111) ligand of the intermediate organometallic species 27b of the acetoxythallation reaction is a very good leaving group [3]. Therefore, a rearrangement occurs which is analogous to that observed in the solvolysis of the 0 (1)-tosylate of selin-7 (1 1)-ene, 1 P-4a-diol [13].…”

Section: C)mentioning

confidence: 81%

New Olefinic Cyclizations by Oxymetallation. Conversion of (−)‐elemol to (−)‐selina‐4α, 11‐diol (cryptomeridiol) and (−)‐guai‐1 (10)‐ene‐4α, 11‐diol

Renold

Ohloff

Norin

1979

Helvetica Chimica Acta

View full text Add to dashboard Cite

Acetoxythallation of (-)-elem01 acetate (lb) yields a diacetate 2b which after treatment with lithium aluminium hydride gives (-)-guai-I (IO)-ene-4a, 1 1 -diol (2a). (-)-Elemol (la) is converted to (-)-selina4a, 1 1-diol (9, cryptomeridiol) by hydroxymercuration followed by reductive demercuration. ( + )-y-Elemene (5) similarly yields (+ )-selin-7 (1 l)-en-4a-ol (11, juniper camphor). The stereochemistry and mechanism of these metal salt-induced olefmic cyclization and their biogenetic implication are discussed.Oxymetallation is a useful tool for the functionalisation of olefins or other nucleophilic substrates [ 11. Thus oxymercuration followed by reductive demercuration represents a simple and convenient procedure for regiospecific (Markovnikovtype) hydration of olefins [2]. Oxythallation is another versatile synthetic method for the oxidation of many types of substrates [3]. Lead tetraacetate represents a classical reagent for the functionalisation of alkenes [4]. Electrophilic metal salts, such as those used in oxymetallation reactions, may also be useful reagents for olefinic cyclizations. There are a few interesting reports [5-111 on this subject (vide infru) although no systematic investigations have been carried out. Further studies in this field should provide useful synthetic tools for olefinic cyclizations or rearrangements and also give valuable information on the stereochemistry and mechanism of metallation reactions. In this paper we report some new regio-and stereospecific olefmic cyclizations induced by thallium (111) and mercury (11) salts.Results. -Treatment of elemol acetate 1 b with thallium (111) nitrate (TTN) in acetic acid for 20 min at room temperature gave a crude diacetate 2b, which was treated with lithium aluminium hydride to give the diol 2a in 63.5%

show abstract

Section: C)mentioning

confidence: 81%

New Olefinic Cyclizations by Oxymetallation. Conversion of (−)‐elemol to (−)‐selina‐4α, 11‐diol (cryptomeridiol) and (−)‐guai‐1 (10)‐ene‐4α, 11‐diol

Renold

Ohloff

Norin

1979

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…pyrrolidone (25 mL) under nitrogen at 25 °C was added bromobutenolide 20 (1.57 g, 8.9 mmol). After 24 h the mixture was poured into 1 N HC1 (100 mL) and extracted with ethyl acetate (3 X 50 mL).…”

mentioning

confidence: 99%

Synthetic approach to the amphilectane diterpenes: the use of nitriles as terminators of carbocation-olefin cyclizations

Stevens¹,

Albizati²

1985

J. Org. Chem.

View full text Add to dashboard Cite

“…(19) We prepared 2 by the reaction shown in Scheme I and dehydrated it after the method described in ref18. This method gave the exo Isomer of 4 in low yield [NMR (CCI4)6 4.0 (m, CHOCH) and 1.0-2.0 (m, 14 H)]. The exo Isomer had a narrower CHOCH multiplet than endoxodecalin (the latter compound has exo hydrogens which couple more strongly than the endo hydrogens of the former compound).…”

mentioning

confidence: 99%

Stereospecific thallium(III) nitrate mediated conversion of bicyclo[3.2.1]-2-octanone to exo-2-norbornanecarboxylic acid methyl ester

Irwin¹,

Jones²

1977

J. Org. Chem.

View full text Add to dashboard Cite

Medium-ring 1,5-dienes. Part III. Cyclisation of germacra-1(10),4,7-(11)-triene oxides

Cited by 17 publications

References 0 publications

New Olefinic Cyclizations by Oxymetallation. Conversion of (−)‐elemol to (−)‐selina‐4α, 11‐diol (cryptomeridiol) and (−)‐guai‐1 (10)‐ene‐4α, 11‐diol

New Olefinic Cyclizations by Oxymetallation. Conversion of (−)‐elemol to (−)‐selina‐4α, 11‐diol (cryptomeridiol) and (−)‐guai‐1 (10)‐ene‐4α, 11‐diol

Synthetic approach to the amphilectane diterpenes: the use of nitriles as terminators of carbocation-olefin cyclizations

Stereospecific thallium(III) nitrate mediated conversion of bicyclo[3.2.1]-2-octanone to exo-2-norbornanecarboxylic acid methyl ester

Contact Info

Product

Resources

About