A straightforward synthesis of glyco-2,7- and 2,8-dienes
摘要:
In this paper, we report the efficient preparation of carbohydrate-derived 2,7- and 2,8-dienes. By our synthetic approach, we have quickly converted D-glucose 1 to (E)-ethyl-2,3-dideoxy-D-gluco-oct-2-enoate 5, which led to the desired (E)-ethyl-9,9-dibromo-2,3,8,9-tetradeoxy-4,5,6,7-tetra-(E)-trimethylsilyl-D-gluco-nona-2,8-dienoate 19 with satisfying yield. (c) 2006 Elsevier Ltd. All rights reserved.
New cytotoxic polyketide macrolides named phormidolidesB and C were isolated from a marine sponge of the Petrosiidae family collected off the coast of Pemba (Tanzania). The isolation, structure elucidation, and enantioselectivesynthesis of three diastereomers of the macrocycliccore is described herein. The described synthetic methodology started from 2‐deoxy‐D‐ribose or 2‐deoxy‐L‐ribose and afforded