TY  - JOUR
A1  - Schmidt, Bernd
A1  - Schultze, Christiane
T1  - A one-pot synthesis of pyranocoumarins through microwave-promoted propargyl claisen rearrangement/wittig olefination
JF  - European journal of organic chemistry
N2  - The reaction between propargyl ethers of hydroxybenzaldehydes and the ylide ethyl (triphenylphosphoranylidene)acetate was carried out under microwave irradiation to regioselectively afford angular pyranocoumarins. The chromene and coumarin heterocyclic scaffolds were simultaneously formed in the same synthetic step without changing the reaction conditions. The natural products seselin, braylin, and dipetalolactone were among the products synthesized by this method.
KW  - Domino reactions
KW  - Alkynes
KW  - Arenes
KW  - Oxygen heterocycles
KW  - Microwave chemistry
KW  - Rearrangement
Y1  - 2017
SN  - 1434-193X
SN  - 1099-0690
VL  - 2018
IS  - 2
SP  - 223
EP  - 227
PB  - Wiley-VCH Verl.
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Riemer, Martin
A1  - Schilde, Uwe
T1  - Tandem Claisen Rearrangement/6-endo Cyclization Approach to Allylated and Prenylated Chromones
JF  - European journal of organic chemistry
N2  - Allyl, dimethylallyl and prenyl ethers derived from o-acyl-phenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandem Claisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones. The method is potentially useful for the synthesis of natural products and drugs.
KW  - Allylic compounds
KW  - Arenes
KW  - Oxygen heterocycles
KW  - Microwave chemistry
KW  - Rearrangement
KW  - Michael addition
Y1  - 2015
U6  - https://doi.org/10.1002/ejoc.201501151
SN  - 1434-193X
SN  - 1099-0690
IS  - 34
SP  - 7602
EP  - 7611
PB  - Wiley-VCH
CY  - Weinheim
ER  -