General and Synthetic Methods: Volume 2 (Specialist Periodical Reports, Band 2) - Softcover

Softcover

ISBN 10: 0851869106 ISBN 13: 9780851869100

Verlag: Royal Society of Chemistry, 1979

Inhaltsangabe

Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.

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A series of reviews by leading specialists in their fields which gives systematic and comprehensive coverage of the progress in major areas of research.

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General and Synthetic Methods Volume 2

A Review of the Literature Published During 1977

By G. Pattenden

The Royal Society of Chemistry

Copyright © 1979 The Chemical Society
All rights reserved.

ISBN: 978-0-85186-910-0

Contents

Chapter 1 Saturated and Unsaturated Acyclic Hydrocarbons By J. Fairhurst, D. C. Harwell, and D. E. Tupper, 1, 
Chapter 2 Aldehydes and Ketones By S. M. Roberts, 30, 
Chapter 3 Carboxylic Acids and Derivatives By D. W. Knight, 67, 
Chapter 4 Alcohols, Halogeno-compounds, and Ethers By R. C. F. Jones, 112, 
Chapter 5 Amines, Nitriles, and Other Nitrogen-containing Functional Groups By E. F. V. Scriven, 141, 
Chapter 6 Organometallics in Synthesis, 
Chapter 7 Saturated Carbocyclic Ring Synthesis By M. Mellor and G. Pattenden, 198, 
Chapter 8 Strategy and Design in Synthesis By S. Turner, 232, 
Reviews on General Synthetic Methods By G. Pattenden, 245, 
Author Index, 250, 

CHAPTER 1

Saturated and Unsaturated Acyclic Hydrocarbons

BY J. FAIRHURST, D. C. HORWELL, AND D. E. TUPPER

1 Introduction

The Report this year is intended to highlight the new synthetic techniques involved in the formation of saturated and unsaturated hydrocarbons, rather than to describe their reactions which lead to additional or alternative functionality. The trends in synthesis in these areas are towards the use of milder reagents to minimize side reactions and towards the application of organometallic reagents in the regio- and stereo-selective formation of unsaturated moieties found in natural products, particularly amongst the terpenoids.

2 Saturated Hydrocarbons

Jackson and co-workers have described a reductive dehydroxylation technique that can be carried out in the presence of a ketone, e.g. the conversion (1)->(2).

Thus, the chloroformates of primary and secondary alcohols, prepared by reaction of the alcohol with phosgene, are reduced to the corresponding alkane in excellent yield on reaction with tri-n-propylsilane in the presence of t-butyl peroxide at 140°C; yields are low for aryl and benzyl alcohols. A method for the direct replacement of the hydroxy-group of alcohols by alkyl or aryl groups has been described (see Scheme 11, ref. 67).

In a series of papers, Caubere and co-workers have described their continued exploration of the use of 'complex reducing agents' in the selective reduction of functional groups. For example, the readily prepared NaH-ButONa-FeCl3 reduces oct-1-ene to n-octane in 90 — 95% yield, and shows selectivity towards exocyclic double bonds. 3 Aliphatic and aromatic halides are reduced to hydrocarbons in high yield by the same reagent, but ketones are unaffected.

Chiral rhodium complexes have found popularity recently in the asymmetric reduction of double bonds bearing polar substituents. However, their application to the asymmetric reduction of hydrocarbon double bonds is limited by their insolubility in non-polar media. Achiwa describes a lipid-soluble complex 'CPPM-rhodium', which consists of two biphosphines as metal ligands and a third lipid-solubilizing group, N-cholesteryloxycarbonyl. Thus, a homogeneous solution of CPPM-rhodium in the olefin (3) gives a quantitative yield of the S-hydrocarbon (4) in 24.7% optical yield. Higher optical yields (<60%) are claimed with the d-trans- 1,2-bis (diphenylphosphinoxy) cyclopentanerhodium complex.

Apparently, halogeno-transition-metal complexes supported on phosphine-modified silica carriers are more active than their homogeneous counterparts by a factor of 2 — 4 orders of magnitude, as measured by their effectiveness on the hydrogenation of cyclohexene.

A new synthetic method for the formal addition of alkanes to olefins has been devised. The alkyl mercuric salt (5) reacts with sodium borohydride in the presence of electron-deficient olefins (6) to form the adduct (7). The yield depends on the mode of addition of NaBH4, the temperature, and the salt :olefin ratio.

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A novel reaction scheme, which in effect makes available the hitherto unattainable transformation {8}->{9}->(10), has been realized using an organoarsenic group as a halogen equivalent (Scheme 1). Here, the halogen atom is replaced by a diphenylarsane oxide (11), effecting the conversion (11)->{12) in 67% yield, leaving the halogen atom intact for further synthetic elaboration. Diphenylvinylarsane has been used to effect a two-carbon chain elongation of lithioalkanes to the corresponding alkyl halides. Alkylhydrazines are oxidized by iodine to give mixtures of alkanes, alkyl iodides, alkenes, and alcohols, depending upon the media and base used. Although yields of alkyl iodides can be good in non-aqueous solvents with a weak base, the yields of alkanes are poor. Trialkylboranes react readily with nitrogen trichloride to give the corresponding alkyl chlorides, 13 and PCl3–DMF has been described as a simple 'brew' for converting primary alcohols into alkyl chlorides.

Diarylmethanols and triarylmethanols are reduced in high yield to the corresponding methanes by NaBH4 in trifluoroacetic acid. Kabalka and co-workers have now extended the use of catecholborane to effect regiospecific deuterium incorporation via the reduction of tosylhydrazones to the corresponding methylene derivatives.

3 Olefinic Hydrocarbons

Reviews have appeared on the use of the Wittig reaction in industrial practice, the Claisen rearrangement, 18 synthetic applications of the retro-Diels–Alder reaction, organo-palladium intermediates for the alkylation and arylation of olefins, the Prins reaction to give 1,3-dienes, and intramolecular [4 + 2] (Diels–Alder) and [3 + 2] cycloadditions. An interesting discussion of the regiospecificity of the Diels–Alder reaction in terms of frontier orbital overlap favours the Woodward–Katz concept. Useful alkyne and polyene coupling reactions are described in reviews on the chemistry of vitamin D,24 the synthesis of insect sex pheromones, and marine natural product chemistry. The polymerization and copolymerization of buta-1,3-diene have also been reviewed.

New fragmentation and elimination processes are being developed, leading to milder reaction conditions for olefin formation. A novel fragmentation of 1-trimethylsilyloxybicyclo[n,1,0]alkanes (13) with lead tetra-acetate affords the terminal olefinic acids (14) by oxidative cleavage of both cyclopropane bonds 'a' and 'b' as depicted in Scheme 2. Trost has reported the first case of carbon serving as a leaving group in a Grob fragmentation of (16) in the stereospecific double chain extension reaction, outlined in Scheme 3, providing (17) from (15) in 85% yield. White has now extended his extrusion reaction by developing routes to a range of sulphoximino-3-amino-2-oxazolidones (18), which on mild thermolyses (<140 °C) undergo syn-elimination to give olefins (Scheme 4). A new mild procedure leading to olefins in good yield has been made available by decarboxylative dehydration of β-hydroxycarboxylic acids (19), utilizing the triphenylphosphine–ethyl azodicarboxylate reagent. 32 Compounds (19) are produced by condensing the dilithium salts of carboxylic acids with carbonyl compounds (Scheme 5).

A convenient synthesis of terminal olefins, which may complement the Wittig reaction, has been reported. The procedure (Scheme 6) involves the addition of a carbon nucleophile, derived from a Grignard or...

Details zur Ausgabe

• Verlag: Royal Society of Chemistry
• Erscheinungsdatum: 1979
• Sprache: Englisch
• ISBN 10: 0851869106
• ISBN 13: 9780851869100
• Einband: Taschenbuch
• Anzahl der Seiten: 276
• Herausgeber: Pattenden G.
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: gpsr@libri.de; gpsr@libri.de; ; Europaallee 1; Bad Hersfeld; 36244; Deutschland