Fuerstner, Alois; Bonnekessel, Melanie; Blank, Jarred T.; Radkowski, Karin; Seidel, Guenter; Lacombe, Fabrice; Gabor, Barbara; Mynott, Richard published the artcile< Total synthesis of myxovirescin A1>, Synthetic Route of 112-63-0, the main research area is myxovirescin A1 total synthesis regioselective Negishi Suzuki coupling; stereoselective hydrogenation oxyallylation total synthesis myxovirescin A1; ring closing metathesis total synthesis myxovirescin A1; hydrosilylation trans total synthesis myxovirescin A1.
A convergent total synthesis of the antibiotic macrolide myxovirescin A1 (I) is described that is largely based on reagent- and catalyst-controlled transformations. This includes a highly regioselective Negishi reaction of dibromo-alkene (E)-BrCH:CBrCH2OMe with an alkynyl-zinc reagent, and a palladium catalyzed alkyl-Suzuki coupling of the resulting enyne derivative (E)-MeC顚咰CH:CBrCH2OMe (II) with the 9-BBN-adduct derived from alkene III. The latter was obtained via an asym. hydrogenation of the chlorinated 尾-ketoester EtO2CCH2COCH2Cl and an anti-selective oxyallylation of the functionalized aldehyde (S)-OHCCH2CH(CH2N3)OCH2OMe as the key steps. The preparation of a bis-borylated allyl-donor used in the oxyallylation step, however, required careful optimization and led to important insights into the nature of the classical hydroborating agent “”di(isopinocampheyl)borane (Ipc2BH)””. It was unambiguously shown by X-ray crystallog. that in the solid state this compound is dimeric, but it is prone to undergo an essentially quant. mono-deborylation when dissolved in CH2Cl2 or benzene; its composition in ethereal solvents is even more complex as evident from 11B NMR data. The product derived from II and III was elaborated into the enyne-yne derivative IV, which served as the substrate for an exquisitely selective ring closing alkyne metathesis reaction (RCAM) catalyzed by a molybdenum tris-amido complex activated in situ with CH2Cl2. The resulting cyclic enyne was subjected to a ruthenium catalyzed trans-hydrosilylation/proto-desilylation tandem. Although [Cp*Ru(MeCN)3]PF6 had previously been recommended as catalyst of choice for trans-hydrosilylation reactions of internal alkynes, this complex failed to afford the desired product, whereas its sterically less hindered congener [CpRu(MeCN)3]PF6 permitted the reaction to be performed in appreciable yield, but at the expense of a lower stereoselectivity. AgF-mediated proto-desilylation of the isomeric silanes followed by cleavage of the remaining acetal protecting groups afforded myxovirescin A1 and its hitherto unknown 14Z-isomer.
Chemistry – A European Journal published new progress about Allylation (oxyallylation). 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Synthetic Route of 112-63-0.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics