Synthetic Photochemistry. XLVI. Cycloaddition of<i>exo</i>,<i>endo</i>-2,7-Bis(methoxycarbonyl)-11,12-dioxatetracyclo[6.2.1.1<sup>3,6</sup>.0<sup>2,7</sup>]dodeca-4,9-diene and Conjugated Enones and<i>p</i>-Quinones
作者:Guan Rong Tian、Akira Mori、Nobuo Kato、Hitoshi Takeshita
DOI:10.1246/bcsj.62.506
日期:1989.2
Photocycloaddition of exo,endo-2,7-bis(methoxycarbonyl)-11,12-dioxatetracyclo[6.2.1.13,6.02,7]dodeca-4,9-diene with conjugated enones and p-quinones occurred exclusively at the exo-addition moiety to give [2+2]cycloadducts. From cyclohexenone, all four possible photoadducts were obtained. A single photoadduct from cyclopentenone was a cis-transoid-cis isomer. Upon thermolysis, cyclobutene derivatives were formed from these photoadducts. An acid treatment of oxetane derivatives derived from photoadducts of p-quinones afforded Michael adducts instead of dienone–phenol rearrangement products.
Photochemical reactions, 135th communication Photochemistry of Homoconjugated Cyclobutanones. II. Decisive Effect ofgem- Dimethyl Substitution on the Course of the Oxa-di-?-methane Rearrangement
作者:Terry A. Lyle、Hari Babu Mereyala、Alfons Pascual、Bruno Frei
DOI:10.1002/hlca.19840670319
日期:1984.5.2
The synthesis and photolysis of the spirocyclobutanones 4–7 incorporating a cyclohexa-, cyclohepta- and cyclooctadiene moiety, respectively, is described. On triplet excitation, these compounds undergo isomerization via a 1,2-acyl shift involving one or both double bonds of the diene system. The presence of a gem-dimethyl group as in 1, 4 and 7 dramatically changes the photoproduct distribution, since
Synthesis of Cycloocta-3,5-dien-1-ol and Cycloocta-3,5-dien-1-one: SeO2/O2 Oxidation of Dienes
作者:Elena S. Koltun、Steven R. Kass
DOI:10.1055/s-2000-7107
日期:——
A useful synthesis of cycloocta-3,5-dien-1-ol was developed starting from cycloocta-1,3-diene. Oxidation of the diene with selenium oxide in refluxing acetic anhydride affords the homoallylic and allylic acetates in a 19 : 1 ratio and a 36% overall yield when O2 is bubbled through the reaction mixture. Subsequent reduction with LAH affords the homoallylic alcohol (95%), which can be readily oxidized via TPAP/N-MMO (73%) to the corresponding non-conjugated dienone. This route represents the most efficient method for the preparation of cycloocta-3,5-dien-1-ol and cycloocta-3,5-dien-1-one reported to date, and may provide a general approach to the synthesis of homoallylic alcohols and non-conjugated enones.
Photochemistry of 2,4-Cyclooctadienone. II In Neutral and Acidic Methanol
作者:Gordon L. Lange、Eli Neidert
DOI:10.1139/v73-333
日期:1973.7.1
Irradiation of 2,4-cyclooctadienone (1) in neutral dry methanol resulted in the formation of 3-methoxy-4-cyclooctenone (18%) and two head-to-head 2 + 2 dimers (combined yield 64%). A similar irradiation in acidic methanol (0.001 N HCl) caused a dramatic change in the products formed. A new compound, the dimethyl ketal of trans, cis-2,4-cyclooctadienone was formed in 67% yield along with the two dimers
[EN] PHOSPHORUS COMPOUNDS AND METHODS THEREOF<br/>[FR] COMPOSÉS PHOSPHORÉS ET LEURS PROCÉDÉS
申请人:AGENCY SCIENCE TECH & RES
公开号:WO2022132048A1
公开(公告)日:2022-06-23
The disclosure concerns phosphorus compounds of formula (I), (II) and (III) and methods of synthesising these compounds. The phosphorus compound can be a cyclic phosphorus compound. The method comprises reacting a compound having two Michael acceptor groups with a hypophosphite ester, acid, salt or solvate thereof and an optional organosilicon compound. The diene can be a cyclodiene.