Total Synthesis of (+)-Phorboxazole A Exploiting the Petasis−Ferrier Rearrangement
作者:Amos B. Smith、Kevin P. Minbiole、Patrick R. Verhoest、Michael Schelhaas
DOI:10.1021/ja011604l
日期:2001.11.1
convergent, stereocontrolled total synthesis of the potent antiproliferative agent (+)-phorboxazole A (1) has been achieved. Highlights of the synthesis include: modified Petasis-Ferrier rearrangements for assembly of both the C(11-15) and C(22-26) cis-tetrahydropyran rings; extension of the Julia olefination to the synthesis of enol ethers; the design, synthesis, and application of a novel bifunctional
L-Threonine was transformed, stereospecifically, to a versatile β-lactam (5a) in 3 steps. This β-lactam was further converted to a key intermediate (25) for the synthesis of thienamycin and its biologically active analogues. Furthermore, the compound 5a was changed to iodides (18 and 23), cyanides (19 and 24), chloromethylketone (26) and aldehydes (30 and 31) which appear to have a latent potential
Facile synthesis of alkyl β-benzyloxyaminocarboxyolates related to monocyclic β-lactams.
作者:Kiyoshi Ikeda、Kazuo Achiwa、Minoru Sekiya
DOI:10.1016/s0040-4039(00)86233-4
日期:1983.1
N-Benzyloxyimines have been shown to react with ketene silyl acetals in the presence of trimethylsilyl triflate catalyst to give alkyl β-benzyloxyaminocarboxylates. Conversion of them to β-lactams has been exemplified.
A convenient synthesis of N-benzyloxy-.BETA.-lactams via N-benzyloxyimines.
作者:Kiyoshi IKEDA、Kazuo ACHIWA、Minoru SEKIYA
DOI:10.1248/cpb.37.1179
日期:——
N-Benzyloxy-β-lactams were prepared from N-benzyloxyimines by reaction with ketene trimethylsilyl acetals in the presence of trimethylsilyl triflate followed by cyclization, or with lithium ester enolates in one step.
Etude de la reaction chlorocarbene-acetals de cetenes
作者:N. Slougui、G. Rousseau
DOI:10.1016/s0040-4020(01)96366-5
日期:1985.1
The reaction of chloro, chloromethyl and chlorophenyl carbenoids with ketene alkylsilylacetals has been studied. Excellent yields of cyclopropanation were observed and the unstable chlorocyclopropanone acetals formed were thermallyrearranged in high yield into α-substituted α,β-ethylenic esters. This new method for the synthesis of unsaturated esters appeared complementary of the known-ones.