A vinylogous urethane approach towards the synthesis of okadaic acid. Construction of the C1-C8 fragment. Part I
摘要:
A vinylogous urethane approach is utilized to synthesize the C1-C8 fragment of okadaic acid. The key steps include an asymmetric alkylation, a hydroxyl directed iodocarbonate cyclization and a stereoselective cyanohydrin formation. (C) 1998 Elsevier Science Ltd. All rights reserved.
A vinylogous urethane approach towards the synthesis of okadaic acid. construction of the C9-C18 Fragment. Part II
作者:Sharon M. Dankwardt、John W. Dankwardt、Richard H. Schlessinger
DOI:10.1016/s0040-4039(98)00972-1
日期:1998.7
diastereo- and enantioselective acylation-reduction sequence of a vinylogous urethane lactone silylketene acetal sets the initial stereocenter in this approach towards the C9-C18 fragment of okadaic acid. The remainder of the stereocenters are installed via a silyl cuprate conjugate addition trapping sequence, and a lactol is transformed to a tetrahydrofuran by addition of a propargyl aluminum species
Synthesis of the C19 through C27 segment of okadaic acid using vinylogous urethane aldol chemistry: Part III
作者:John W. Dankwardt、Sharon M. Dankwardt、Richard H. Schlessinger
DOI:10.1016/s0040-4039(98)00973-3
日期:1998.7
The synthesis of the C-19 through C-27segment of the marine natural product okadaic acid was accomplished employing a highly enantio- and diasteroselective aldol coupling reaction of a chiral vinylogous urethane lactone enolate. The remainder of the carbon skeleton of this segment was constructed by a diastereoselective γ-oxygenated allylstannane addition. Formation of the tetrahydropyran ring was
A vinylogous urethane approach towards the synthesis of okadaic acid. Construction of the C1-C8 fragment. Part I
作者:Sharon M. Dankwardt、John W. Dankwardt、Richard H. Schlessinger
DOI:10.1016/s0040-4039(98)00971-x
日期:1998.7
A vinylogous urethane approach is utilized to synthesize the C1-C8 fragment of okadaic acid. The key steps include an asymmetric alkylation, a hydroxyl directed iodocarbonate cyclization and a stereoselective cyanohydrin formation. (C) 1998 Elsevier Science Ltd. All rights reserved.
Highly diastereoselective alkylation reactions of vinylogous urethanes derived from simple tetronic acids
作者:Richard H. Schlessinger、Edwin J. Iwanowicz、James P. Springer
DOI:10.1016/s0040-4039(00)80332-9
日期:——
The lithiumenolates generated from the tetronic acid derived vinylogous urethanes 3 and 4 have been found to undergo alkylation reactions with a variety of electrophiles to give products with predictable stereochemistry accompanied by very high diastereoselectivity.