Mukaiyama-Michael reaction of cyclic ketene silyl acetals and enones. Importance of ring flexibility in electron transfer process
作者:Yukihiro Fujita、Shunichi Fukuzumi、Junzo Otera
DOI:10.1016/s0040-4039(97)00321-3
日期:1997.3
Michael reaction of macrocyclic ketenesilylacetals or α-enones occurs smoothly under electrontransfer conditions while the reaction of 6-membered analogs is more sluggish, indicating the importance of the ring flexibility to allow the α,β-carbon-carbon bonds of both reaction components to rotate when the radical species are generated.
Chemo-Enzymatic Oxidative Rearrangement of Tertiary Allylic Alcohols: Synthetic Application and Integration into a Cascade Process
作者:Elisabetta Brenna、Michele Crotti、Matteo De Pieri、Francesco G. Gatti、Gabriele Manenti、Daniela Monti
DOI:10.1002/adsc.201800299
日期:2018.10.4
developed to easily transform a cyclopentenone derivative into trans‐Magnolione® and dehydro‐Magnolione®. The rearrangement of exocyclic allylic alcohols was tested as well, and a dynamic kinetic resolution was observed: α,β‐unsaturated ketones with (E)‐configuration and a high diastereomeric excess were synthesized. Finally, the 2,2,6,6‐tetramethyl‐1‐piperidinium tetrafluoroborate (TEMPO+BF4−)/laccase
SmI2-promoted conjugate reduction of α,β-unsaturated esters and ketones studied in comparison with Mukaiyama-Michael reaction of ketene silyl acetal
作者:Yukihiro Fujita、Shunichi Fukuzumi、Junzo Otera
DOI:10.1016/s0040-4039(97)00322-5
日期:1997.3
SmI2-promoted conjugate reduction of α,β-unsaturated esters and ketones proceeds in a manner quite similar to Mukaiyama-Michael reaction of ketene silyl acetal. The more substituted esters are reduced more preferentially than the less substituted ones. The substrates with a 12 or 16 membered-ring structure undergo reduction smoothly. On the other hand, the 6-membered substrates completely fail to react