Polyhydroxylated pyrrolizidines. Part 6: A new and concise stereoselective synthesis of (C)-casuarine and its 6,7-diepi isomer, from DMDP
نویسندگان
چکیده
A new synthesis for (C)-casuarine (1) and its 6,7-diepi isomer (15) in a stereocontrolled manner, is reported herein. An appropriately protected polyhydroxylated pyrrolidine, such as (2R,3R,4R,5R)-3,4-dibenzyloxy-2 0-O-tert-butyldiphenylsilyl-2,5bis(hydroxymethyl)pyrrolidine (3, protected DMDP), easily available from D-fructose, was chosen as the chiral starting material. Compounds 1 and 15 were obtained from 3, in seven steps, in a 23.2 and 20.5% overall yields, respectively. q 2005 Elsevier Ltd. All rights reserved. Figure 1. (C)-Casuarine (1).
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