A regioselective 8-endo-trig aryl radical cyclisation of the 5,6-deoxy-D-xylo-5-enofuranosides 3a and 3b with tri-n-butyltin hydride provides the chiral furo[3,2-c][2]benzoxocines 4a and 4b in good yields; the crystal structure of 4a is reported.
Radical cyclization of exo-methylene furanose derivatives: an expedient approach to the synthesis of chiral tricyclic nucleosides and benzannulated oxepine derivatives
作者:Arpita Neogi、Tirtha Pada Majhi、Nanda Ghoshal、Partha Chattopadhyay
DOI:10.1016/j.tet.2005.07.054
日期:2005.9
Tributyltin radical mediated cyclization of the glucose derived exo-methylene furanose derivatives 5a-c led to the highly functionalized cis-fused bicyclic ethers 6a-c. The product could subsequently be transformed to the optically active tricyclic nucleoside analogue 8 or oxepine derivative 9. (c) 2005 Elsevier Ltd. All rights reserved.
Sequential Baylis–Hillman reaction and radical cyclization of furanose derivatives: expeditious approach to enantiopure benzo-fused nine-membered oxacycles
作者:Tirtha Pada Majhi、Arpita Neogi、Soumen Ghosh、Alok Kumar Mukherjee、Partha Chattopadhyay
DOI:10.1016/j.tet.2006.09.080
日期:2006.12
A regioselective 9-endo-trig aryl radical cyclization of D-glucose derived diastereomeric Baylis-Hillman reaction products with Bu3SnH led to highly functionalized tricyclic benzannulated ethers incorporating cis- and trans-9,5 bicyclic systems in good yields. Degradation of one of the products afforded an enantiopure multifunctionalized benzoxonine derivative. (c) 2006 Elsevier Ltd. All rights reserved.
Nandi; Mukhopadhyay; Chattopadhyay, Journal of the Chemical Society. Perkin Transactions 1 (2001), 2001, # 24, p. 3346 - 3351