Synthesis of Substituted Benzaldehydes via a Two-Step, One-Pot Reduction/Cross-Coupling Procedure
作者:Dorus Heijnen、Hugo Helbert、Gert Luurtsema、Philip H. Elsinga、Ben L. Feringa
DOI:10.1021/acs.orglett.9b01274
日期:2019.6.7
The synthesis of functionalized (benz)aldehydes, via a two-step, one-pot procedure, is presented. The method employs a stable aluminum hemiaminal as a tetrahedral intermediate, protecting a latent aldehyde, making it suitable for subsequent cross-coupling with (strong nucleophilic) organometallic reagents, leading to a variety of alkyl and aryl substituted benzaldehydes. This very fast methodology
Synthesis of the forskolin skeleton via anionic oxy-cope rearrangement
作者:Jeffrey A. Oplinger、Leo A. Paquette
DOI:10.1016/s0040-4039(00)96749-2
日期:1987.1
The forskolin prototype 14 has been elaborated in 9 steps from 2,4,4-trimethylcyclohexenone (5), the entire ring system materializing during oxyanionic Cope rearrangement of alcohol 10.
most reactive bis[2-(4,5-dihydrofuryl)]methyl-silane (7). The reaction of tris-heteryl-silanes and -germanes with LiAlH4 gives [2-(4,5-dihydrofuryl)]methylsilane (12), [2-(5,6-dihydro-4H-pyranyl)]methylsilane (14) and [2-(4,5-dihydrofuryl)]methylgermane (13) in good yields, which are otherwise difficult to obtain.
The organocuprates derived from reaction of Grignard reagents with CuBr·Me2S react with 5-lithio-2,3-dihydrofuran and 6-lithio-3,4-dihydro-2H-pyran via a 1,2-metallate rearrangement to generate an alkenylmagnesium cuprate.
The regiospecific synthesis of angularly-fused xanthones via the benzannulation of 1,2-adducts derived from 3-(o-anisoyl)-4-substituted cyclobutenediones and their dithianyl derivatives
作者:Lijun Sun、Lanny S. Liebeskind
DOI:10.1016/s0040-4039(97)00720-x
日期:1997.5
Described in this paper is a new synthetic approach to angularly-fused and simpler substituted xanthones that is based upon the benzannulation of 2-(o-anisoyl)-4-heteroaryl-2-cyclobutenones and 2-(2-(o-anisyl)-1,3-dithian-2-yl)-4-alkenyl-2-cyclobutenones followed by facile intramolecular loss of methanol and cyclization to the xanthone.