@article { ISI:000244732800019, title = {Stereoselective synthesis of 3-alkylidene/alkylazetidin-2-ones from azetidin-2,3-diones}, journal = {Tetrahedron}, volume = {63}, number = {11}, year = {2007}, month = {MAR}, pages = {2524-2534}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Azetidin-2,3-diones have been used as synthons for the synthesis of C-3 alkylidene/alkylazetidin-2-ones. Some of the 3-alkylazetidin-2-ones are well known for their cholesterol absorption inhibitor activity. A regio and stereoselective Grignard reaction on a keto group followed by dehydration using PPh3/CCl4 reagent is a key step in this synthesis. Hydrogenation of the 3-alkylideneazetidin-2-ones provided stereoselectively cis-3-alkylazetidin-2-ones in very good yields. (c) 2006 Published by Elsevier Ltd.

}, keywords = {3-diones, azetidin-2, azetidin-2-ones, beta-lactam, Grignard reaction}, issn = {0040-4020}, doi = {10.1016/j.tet.2006.12.010}, author = {Tiwari, Dharmendra Kumar and Shaikh, Ashif Y. and Pavase, Laxmikant S. and Gumaste, Vikas K. and Deshmukh, Abdul Rakeeb A. S.} } @article { ISI:000267070700046, title = {Enantioselective total synthesis of (2S,3R,4R)-D-xylo-phytosphingosine from substituted azetidin-2-one}, journal = {Tetrahedron Letters}, volume = {50}, number = {26}, year = {2009}, month = {JUL}, pages = {3296-3298}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Enantiomerically pure (2S,3R,4R)-D-xylo phytosphingosine is synthesized in 36\% overall yield in seven steps from known beta-lactam (8) derived from D-mannitol triacetonide. (C) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {beta-lactam, Enantioselective synthesis, Sphingosine, Wittig reaction}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2009.02.050}, author = {Pandey, Ganesh and Tiwari, Dharmendra Kumar} } @article { ISI:000341360400024, title = {Divergent total synthesis of 1,6,8a-tri-epi-castanospermine and 1-deoxy-6,8a-di-epi-castanospermine from substituted azetidin-2-one (beta-lactam), involving a cascade sequence of reactions as a key step}, journal = {Organic \& Biomolecular Chemistry}, volume = {12}, number = {37}, year = {2014}, month = {JUL}, pages = {7389-7396}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A divergent, short, and novel total synthesis of 1,6,8a-tri-epi-castanospermine (7) and 1-deoxy-6,8a-di-epi-castanospermine (8) has been developed via a common precursor, 15, obtained from D-mannitol derived beta-lactam. The key step involves a one pot cascade sequence of trimethyl sulfoxonium ylide based cyclization of epoxy sulfonamide 14 via epoxide ring opening, one carbon homologation followed by intramolecular cyclization.

}, issn = {1477-0520}, doi = {10.1039/c4ob00948g}, author = {Tiwari, Dipak Kumar and Bharadwaj, Kishor Chandra and Puranik, Vedavati G. and Tiwari, Dharmendra Kumar} }