5709-99-9Relevant articles and documents
Enantioselective synthesis of chiral sulfones by ir-catalyzed asymmetric hydrogenation: A facile approach to the preparation of chiral allylic and homoallylic compounds
Zhou, Taigang,Peters, Byron,Maldonado, Matias F.,Govender, Thavendran,Andersson, Pher G.
, p. 13592 - 13595 (2012/10/08)
A highly efficient and enantioselective Ir-catalyzed hydrogenation of unsaturated sulfones was developed. Chiral cyclic and acyclic sulfones were produced in excellent enantioselectivities (up to 98% ee). Coupled with the Ramberg-Baecklund rearrangement, this reaction offers a novel route to chiral allylic and homoallylic compounds in excellent enantioselectivities (up to 97% ee) and high yields (up to 94%).
Nucleo-δ-peptides Derived from Conformationally Constrained Nucleo-δ-amino Acids: Preparation of Monomers
Karig, Gunter,Fuchs, Andreas,Buesing, Arne,Brandstetter, Tilmann,Scherer, Stefan,Rats, Jan W.,Eschenmoser, Albert,Quinkert, Gerhard
, p. 1049 - 1078 (2007/10/03)
Cyclic nucleo-δ-amino-acids that constitute monomers of a conformationally constrained nucleo-δ-peptide base-pairing system have been prepared. Their synthesis starts with an enantioselectively analyzed chirogenic Diels-Alder reaction, proceeds via a regioselective ε-iodolactamisation process, and ends with a regio- as well as stereoselective introduction of nucleobases through SN2-type opening of a transiently formed N-acylaziridine ring. Extensive use of X-ray crystal-structure analysis has been made to support structure assignments.
Synthesis of a C22-34 subunit of the immunosuppressant FK-506
Marshall,Xie
, p. 7230 - 7237 (2007/10/03)
A new route to the C22-34 subunit of FK-506 was developed. A highly diastereoselective Diels-Alder reaction of 1,3-butadiene with the bis-acrylate of (R,R)-hydrobenzoin and subsequent saponification provided the cyclohexenecarboxylic acid 6.4 of 95% ee. Elaboration to the enal 9.2 was effected by known transformations. Enal 9.2 underwent diastereoselective and enantiospecific S(E)2' addition of allenyl stannane (S)-3.9 affording the homopropargylic alcohol 9.3 as an 85:15 syn/anti mixture. The PMB ether 9.5 was converted to the known benzylidene derivative 10.4 by sequential treatment with Red-Al, epoxidation, a second reduction with Red-Al, and oxidative benzylidene formation with DDQ.