@article { ISI:000233495500001, title = {Concise account of recent S(N)2 {\textquoteleft} grignard coupling reactions in organic synthesis}, journal = {Synthesis-Stuttgart}, number = {18}, year = {2005}, month = {NOV}, pages = {2995-3022}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

Over the past few decades studies oil controlling the chemo-, regio- and stereoselectivities of allylic Substitution reactions have been well documented in the literature and the S(N)2{\textquoteright} Grignard coupling reaction has emerged as a very powerful tool ill selective carbon-carbon bond formation. This review focuses on all the recent synthetic developments in this special class of reactions. 1 Introduction 2 S(N)2{\textquoteright} Grignard Coupling Reactions with Allylic Substrates 2.1 Allyl Halides 2.2 Allyl Acetates 2.3 Allyl Carbonates 2.4 Allyl Carbamates 2.5 Allyl Ethers 2.6 Allyl Silyl Ethers 2.7 Allyl Epoxides 2.8 Allyl Aziridines 2.9 Allyl Oxazolidinones 2.10 Allyl Thioethers 2.11 Allyl Benzotriazoles 2.12 Oxabicyclic Alkenes 2.13 Azabicyclic Alkenes 2.14 Oxa-azabicyclic Alkenes 3 S(N)2{\textquoteright} Grignard Coupling Reactions with Propargyl Substrates 3.1 Propargyl Acetates 3.2 Propargyl Silyl Ethers 3.3 Propargyl Epoxides 3.4 Propargyl Aziridines 3.5 Propargyl Dithioacetals 3.6 Propargyl Thioethers 4 S(N)2{\textquoteright} Grignard Coupling Reactions with Bromoallenes 5 S(N)2{\textquoteright} Grignard Coupling Reactions in Natural/Unnatural Product Synthesis 6 Conclusions.

}, keywords = {allylic substrates, bromoallenes, chiral/achiral S(N)2 {\textquoteleft} Grignard coupling reactions, Natural products, propargyl Substrates}, issn = {0039-7881}, doi = {10.1055/s-2005-918455}, author = {Kar, Anirban and N. P. Argade} } @article { ISI:000231847000003, title = {Facile synthesis of rubrolide E}, journal = {Synthesis-Stuttgart}, number = {14}, year = {2005}, month = {SEP}, pages = {2284-2286}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A simple and efficient synthesis of rubrolide E (1e) has been demonstrated via Meerwein coupling reaction of para-anisyl-diazonium chloride with N-phenylmaleimide (2), regioselective reduction of para-anisylmaleic anhydride (4), Knoevenagel condensation of butyrolactone 5 with para-anisaldehyde and demethylation pathway.

}, keywords = {Knoevenagel condensation, Meerwein coupling, N-phenylmaleimide, regioselective reduction, rubrolide E, Total synthesis}, issn = {0039-7881}, doi = {10.1055/s-2005-869995}, author = {Kar, Anirban and N. P. Argade} } @article { ISI:000229376400004, title = {Simple synthesis of (+/-)-sarkomycin}, journal = {Synthesis-Stuttgart}, number = {8}, year = {2005}, month = {MAY}, pages = {1234-1236}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A facile 6-step route to (+/-)-sarkomycin in 17\% overall yield has been described via Michael addition of nitromethane to 2-hydroxymethyl-2-cyclopentenone, oxone-induced oxidative Nef reaction, and acid catalyzed dehydration.

}, keywords = {(+/-)-sarkomycin synthesis, 2-hydroxymethyl-2-cyclopentenone, Michael addition, nitromethane., oxidative Nef reaction, Oxone}, issn = {0039-7881}, doi = {10.1055/s-2005-861877}, author = {Kar, Anirban and N. P. Argade} } @article { ISI:000229484400013, title = {Synthesis of naturally occurring bioactive butyrolactones: maculalactones A-C and nostoclide I}, journal = {Tetrahedron}, volume = {61}, number = {22}, year = {2005}, month = {MAY}, pages = {5297-5302}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Starting from citraconic anhydride (13), a simple multistep (9-10 steps) synthesis of naturally occurring butyrolactones maculalactone A (3), maculalactone B (1), maculalactone C (2) and nostoclide 1 (4) have been described with good overall yields via dibenzylmaleic anhydride (20) and benzylisopropylmaleic anhydride (27). The two anhydrides 20 and 27 were prepared by S(N)2{\textquoteright} coupling reactions of appropriate Grignard reagents with dimethyl bromomethylfumarate (14), LiOH-induced hydrolysis of esters to acids, bromination of carbon-carbon double bond, in situ dehydration followed by dehydrobromination and chemoselective allylic substitution of bromoatom in disubstituted anhydrides 19 and 26 with appropriate Grignard reagents. The NaBH4 reduction of these anhydrides 20 and 27 furnished the desired lactones 21 and 29, respectively. The lactone 21 on Knoevenagel condensation with benzaldehyde, furnished maculalactone B (1), which on isomerization gave maculalactone C (2). Selective catalytic hydrogenation of 1 gave maculalactone A (3). The conversion of lactone 29 to nostoclide 1 (4) is known. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {dimethyl bromomethylfumarate, disubstituted maleic anhydrides, maculalactone A-C, NaBH4 reductions, nostoclide 1, S(N)2 {\textquoteleft} Grignard couplings, synthesis}, issn = {0040-4020}, doi = {10.1016/j.tet.2005.03.065}, author = {Kar, Anirban and Gogoi, Sanjib and N. P. Argade} }