@article { ISI:000280541800020, title = {Isochroman- and 1,3-dihydroisobenzofuran-annulation on carbohydrate templates via [2+2+2]-cyclotrimerization and synthesis of some tricyclic nucleosides}, journal = {Tetrahedron}, volume = {66}, number = {32}, year = {2010}, month = {AUG}, pages = {6085-6096}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The synthesis of enantiopure tricyclic systems comprising isochroman or dihydroisobenzofuran units integrated with sugar templates has been documented. The alkyne cylotrimerization reaction has been employed with easily accessible sugar diynes for the key bicyclic ring construction and thus a provision to alter the functional groups on the newly formed aromatic rings. By selecting two representative trimerization products, we have synthesized the tricyclic nucleosides by simple synthetic manipulations. (c) 2010 Elsevier Ltd. All rights reserved.

}, keywords = {Dihydroisobenzofuran, Dihydroisobenzopyran, Modified nucleosides, Vorbruggen reaction, [2+2+2] cyclotrimerization}, issn = {0040-4020}, doi = {10.1016/j.tet.2010.06.011}, author = {Suryawanshi, Sharad B. and Dushing, Mangesh P. and Gonnade, Rajesh G. and Ramana, C. V.} } @article { ISI:000294145600011, title = {Target cum flexibility: synthesis of C(3 {\textquoteleft})-spiroannulated nucleosides}, journal = {Tetrahedron Letters}, volume = {52}, number = {36}, year = {2011}, month = {SEP}, pages = {4627-4630}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

We report a simple strategy for the synthesis of a collection of C(3{\textquoteright})-spirodihydroisobenzo-furannulated nucleosides featuring a [2+2+2]-cyclotrimerization as the key reaction. The cyclotrimerization reactions are facile with the unprotected nucleosides having a diyne unit. When both alkynes of the diyne are terminal, the regioselectivity is poor. However, when one of the terminal alkynes is additionally substituted, the cyclotrimerizations are highly diastereoselective. Since the key bicycloannulation is the final step, this strategy provides flexibility in terms of the alkynes and is thus amenable for the synthesis of a focussed small molecule library. (C) 2011 Published by Elsevier Ltd.

}, keywords = {Dihydroisobenzofuran, Modified nucleosides, Tanaka catalyst, Willkinson catalyst, [2+2+2]-Cyclotrimerization}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2011.06.100}, author = {Dushing, Mangesh P. and Ramana, C. V.} } @article {43898, title = {Phenol oxidative dearomatization of modified nucleoside templates: a simple access to the c7-spiroannulated octosyl acid framework}, journal = {Synthesis-Stuttgart}, volume = {49}, year = {2017}, month = {SEP}, chapter = {4221-4228}, abstract = {

Phenol oxidative dearomatization and cyclization has been executed successfully on nucleoside templates to synthesize C7-spiroannulated perhydrofuropyran nucleosides and C6-spiroannulated perhydrofurofuran nucleosides as novel analogues of octosyl acid and related peptidyl nucleosides.

}, keywords = {Analogs, antibiotics, Biosynthesis, Chitin synthase, Derivatives, Ezomycins, Glucose Diacetonide Natural-products, Griseofulvin, Malayamycin, Modified nucleosides, Moiety, Peptidyl Glycosides, Phenol Oxidative Dearomatization, Vorbruggen Glycosylation}, issn = {0039-7881}, doi = {10.1055/s-0036-1588543}, author = {Mullapudi, Venkannababu and Bhogade, Ravindra B. and Deshpande, Mukund V. and Ramana, Chepuri V.} }