Take you to know Samarium Fluoride SmF3
The total synthesis of Samarium Fluoride SmF3 and paclitaxel was successful at -78℃, the yield was 70%, and the stereoselectivity was greater than 4:1. It occupies four carbon atoms in the octahedral ring, and its structure is novel and difficult to synthesize. Using smlz, molander successfully constructed the octagonal skeleton "3" of (-)-steganone. Moran also used samarium fluoride in the synthesis of the (-)-cryptanone analog (+)-isoschisandrin.
The axial chirality of compound 14 effectively controls the chirality of the product, and the Z-type double bond also plays an important role in the reaction. The complexes of HMPA and SML form calcium alkoxides in the saddle oxygen reaction system. Several complexes of HMPA with SM increase their bulk, effectively controlling the configuration of the transition state. Oxygen cyclization is notoriously strong affinity.
The smlz-mediated intramolecular cyclization of pinacol tends to generate cis-diols due to the complex between Samarium Fluoride SmF3. If there is an alkoxy substituent in the alpha position, the majority of these reaction products are newly formed in the opposite direction to the original alkoxy group.
In the synthesis of paclitaxel octahedral backbone, Samarium Fluoride SmF3-mediated intramolecular cyclization of pinacol was employed. The results showed that the newly formed diol in the product was trans. It is well known that the stable conformation of the octane ring is a boat-chair, and samarium fluoride believes that the formation of the trans-diol should be attributed to the transition state structure of the analogous product.