Functionalized Small & Medium Carbocycles |
---|
|
ÀϽà : 2019.10.02 17:00 |
¼Ò¼Ó : ¼¿ï´ë ÀÀ¿ë»ý¹°ÈÇкΠ|
¹ßÇ¥ÀÚ : ±Ç¿ëÈÆ |
Àå¼Ò : R404 |
The development of ring closing alkyne metathesis (RCAM) followed by stereoselective reduction of the resulting alkyne has rendered opportunities to access macrolides as well as medium-sized carbocycles bearing Z- or E-alkenes.1 Beyond the selective formation of (Z)- or (E)-disubstituted alkenes, we recently demonstrated that a macrolide having a trisubstituted alkene with well-defined stereochemistry can be prepared by a RCAM/trans-selective hydrostannation sequence. This approach is complementary to ring closing alkene metathesis (RCM) since (stereoselective) formation of trisubstituted alkenes by RCM is problematic. Testing this method in the total synthesis of a complex natural product is desirable to broaden the generality of the strategy. Disciformycins A and B, isolated from cultures of Pyxidicoccus fallax by the Müller group in 2014,2 were chosen as our targets as they exhibit considerable antibacterial activity against Gram-positive bacteria. This presentation will describe details of unforeseen synthetic challenges and our endeavors to resolve these problems met along the way. |