Cycloaddition reactions of silyloxyacetylenes with ketenes: synthesis of cyclobutenones, resorcinols, and .DELTA.-6-tetrahydrocannabinol
作者:Conrad J. Kowalski、G. Sankar. Lal
DOI:10.1021/ja00219a073
日期:1988.5
La cycloaddition du cetene avec des composes acetyleniques donne des cyclobutene-2ones. Ces dernieres reagissent avec des composes acetyleniques pour donner des resorcinols et le tetrahydro-6a,7,10,10a cannabinol
La cycloaddition du cetene avec des composes acetyleniques donne des cyclobutene-2ones。Ces dernieres reagissent avec des composes acetyleniques pour donner des resorcinols et le tetrahydro-6a,7,10,10a 大麻
Synthesis of Polycyclic Benzofused Nitrogen Heterocycles via a Tandem Ynamide Benzannulation/Ring-Closing Metathesis Strategy. Application in a Formal Total Synthesis of (+)-FR900482
作者:Xiao Yin Mak、Aimee L. Crombie、Rick L. Danheiser
DOI:10.1021/jo2000308
日期:2011.3.18
variety of functionalized substituents at the position ortho to the nitrogen. In the second stage of the tandem strategy, ring-closingmetathesis generates the nitrogen heterocyclic ring. This two-step sequence provides efficient access to highly substituted dihydroquinolines, benzazepines, benzazocines, and related benzofused nitrogen heterocyclic systems. The application of this chemistry in a concise
Enantioselective Synthesis of 3‐Substituted Cyclobutenes by Catalytic Conjugate Addition/Trapping Strategies
作者:Changxu Zhong、Yingchao Huang、Haocheng Zhang、Qiang Zhou、Yu Liu、Ping Lu
DOI:10.1002/anie.201913825
日期:2020.2.10
A copper-catalyzed tandem process to generate chiral cyclobutene derivatives has been developed. It is based on an enantioselective conjugate addition or reduction of a cyclobutenone and sequential trapping with a chlorophosphate in a one-pot process. These phosphates are stable under mildly acidic conditions and serve as good electrophiles in Negishi coupling reactions.
Regiodivergent Cyclobutanone Cleavage: Switching Selectivity with Different Lewis Acids
作者:Laetitia Souillart、Nicolai Cramer
DOI:10.1002/chem.201406135
日期:2015.1.26
diverse building blocks. Herein, Lewisacidcatalyzed rearrangement reactions are presented that provide selective access to two structurally distinct polycyclic scaffolds, that is, indenylacetic acid derivatives and benzoxabicyclo[3.2.1]octan‐3‐ones. The choice of the Lewisacid fully controls the reactionpathway and the regioselectivity of the cyclobutanone CCbondcleavage site.
Photochemical generation of vinylketenes by electrocyclic opening of cyclobutenones
作者:Alfred Hassner、Simha Naidorf
DOI:10.1016/s0040-4039(00)87816-8
日期:1986.1
4-Dich1oro-2-cyclobutenones , available by cycloaddition of acetylenes to dichloroketene, can be photolyzed in the presence of olefins or dienes to produce regiospecifically 2-vinylcyclobutanones . The photochemical reaction succeeds even in some cases where thermolysis fails and was shown to proceed by electrocyclic ring opening to a vinylketene. Stereochemically the results of photolysis of differ from thermolysis