619335-75-0Relevant articles and documents
Formal total synthesis of (-)-taxol through Pd-catalyzed eight-membered carbocyclic ring formation
Hirai, Sho,Utsugi, Masayuki,Iwamoto, Mitsuhiro,Nakada, Masahisa
supporting information, p. 355 - 359 (2015/02/19)
A formal total synthesis of (-)-taxol by a convergent approach utilizing Pd-catalyzed intramolecular alkenylation is described. Formation of the eight-membered carbocyclic ring has been a problem in the convergent total synthesis of taxol but it was solved by the Pd-catalyzed intramolecular alkenylation of a methyl ketone affording the cyclized product in excellent yield (97 %), indicating the high efficiency of the Pd-catalyzed intramolecular alkenylation. Rearrangement of the epoxy benzyl ether through a 1,5-hydride shift, generating the C3 stereogenic center and subsequently forming the C1-C2 benzylidene, was discovered and utilized in the preparation of a substrate for the Pd-catalyzed reaction.
Preparation of new chiral building blocks: Highly enantioselective reduction of prochiral 1,3-cycloalkanediones possessing a methyl group and a protected hydroxymethyl group at their C2 position with Baker's yeast or CBS catalyst
Watanabe, Hideaki,Iwamoto, Mitsuhiro,Nakada, Masahisa
, p. 4652 - 4658 (2007/10/03)
Highly enantioselective reduction of five-, six-, seven-, and eight-membered prochiral 1,3-cycloalkanediones possessing a methyl group and a protected hydroxymethyl group at their C2 position with baker's yeast or CBS catalyst and a new efficient and general method for preparing the 1,3-cycloalkanediones have been developed. These baker's yeast mediated reductions were found to produce corresponding ketols with high optical purity (> 99% ee) and high yield. All of the prepared ketols and their derivatives, chiral building blocks, have been fully characterized, and their absolute configurations have been determined. These compounds would be useful for the convergent synthesis of complex natural products.
Synthetic studies on the taxane skeleton: Construction of eight-membered carbocyclic rings by the intramolecular B-alkyl Suzuki-Miyaura cross-coupling reaction
Kawada, Hatsuo,Iwamoto, Mitsuhiro,Utsugi, Masayuki,Miyano, Masayuki,Nakada, Masahisa
, p. 4491 - 4494 (2007/10/03)
(Chemical equation presented) Construction of eight-membered carbocyclic rings via the intramolecular B-alkyl Suzuki-Miyaura cross-coupling reaction has been studied. This protocol proved its potency through the formation of the eight-membered ring posses
Preparation of new chiral building blocks via asymmetric catalysis
Iwamoto, Mitsuhiro,Kawada, Hatsuo,Tanaka, Tomoyuki,Nakada, Masahisa
, p. 7239 - 7243 (2007/10/03)
Highly enantio- and stereoselective preparation of some new chiral building blocks with baker's yeast or the CBS catalyst is described.
