Weisser Roland, Yue Weimin, Reiser Oliver
Institut für Organische Chemie der Universität Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany.
Org Lett. 2005 Nov 24;7(24):5353-6. doi: 10.1021/ol051457m.
[structure: see text] A short and enantioselective synthesis of cis-fused 5-oxofuro[2,3-b]furans, being found in many spongiane diterpenoid natural products, is reported starting from inexpensive methyl 2-furoate. Moreover, the acid-catalyzed rearrangement of the furo[2,3-b]furan framework A to B is observed for some derivatives, suggesting a simple connection between natural products differing in the absolute configuration of the 3a,6a ring junction.
[结构：见正文] 报道了一种从廉价的2-呋喃甲酸甲酯出发，对许多海绵二萜类天然产物中存在的顺式稠合5-氧代呋喃并[2,3-b]呋喃进行的简短且对映选择性合成。此外，观察到一些衍生物的呋喃并[2,3-b]呋喃骨架A到B的酸催化重排，这表明在3a,6a环连接的绝对构型不同的天然产物之间存在简单的联系。
