TY - JOUR
T1 - α-Activated cross conjugated cycloalkenone systems in organic synthesis
AU - Wu, Yen-Ku
AU - Ly, Tai Ei
AU - Shia, Kak Shan
PY - 2010/6/25
Y1 - 2010/6/25
N2 - Under catalysis with an appropriate Lewis acid, the intermolecular Diels-Alder cycloaddition and intramolecular polyene cyclization of the α-activated cross conjugated cycloalkenone systems, possessing particularly increased dienophilicity/electrophilicity in the cross conjugated double bond, proceeded constantly with a high degree of stereochemical control, leading to a variety of synthetically useful molecules, which may serve as advanced intermediates towards many structurally challenging natural products, especially cis-clerodane diterpenoids. Mechanistically, an additional conjugated double bond incorporated into the synthetically useful molecules, which may serve as advanced intermediates towards many structurally challenging natural products, especially cis-clerodane diterpenoids. Mechanistically, an additional conjugated double bond incorporated into the cycloalkenone core of the titled systems might contribute synergistically to the classical secondary orbital effects, thus significantly enhancing the endo-to-ketone addition. In addition, a tandem multiple-bond migration process, an enzymatic pathway prevalent in nature, was proposed to rationalize the formation of structurally unusual polyene-cyclization products occurring under standard chemical conditions.
AB - Under catalysis with an appropriate Lewis acid, the intermolecular Diels-Alder cycloaddition and intramolecular polyene cyclization of the α-activated cross conjugated cycloalkenone systems, possessing particularly increased dienophilicity/electrophilicity in the cross conjugated double bond, proceeded constantly with a high degree of stereochemical control, leading to a variety of synthetically useful molecules, which may serve as advanced intermediates towards many structurally challenging natural products, especially cis-clerodane diterpenoids. Mechanistically, an additional conjugated double bond incorporated into the synthetically useful molecules, which may serve as advanced intermediates towards many structurally challenging natural products, especially cis-clerodane diterpenoids. Mechanistically, an additional conjugated double bond incorporated into the cycloalkenone core of the titled systems might contribute synergistically to the classical secondary orbital effects, thus significantly enhancing the endo-to-ketone addition. In addition, a tandem multiple-bond migration process, an enzymatic pathway prevalent in nature, was proposed to rationalize the formation of structurally unusual polyene-cyclization products occurring under standard chemical conditions.
KW - Cross conjugated
KW - Cycloaddition
KW - Diels-Alder reaction
KW - Lewis acids
KW - Polyene cyclization
UR - http://www.scopus.com/inward/record.url?scp=77953771762&partnerID=8YFLogxK
U2 - 10.2174/157017910790820328
DO - 10.2174/157017910790820328
M3 - Article
AN - SCOPUS:77953771762
VL - 7
SP - 78
EP - 93
JO - Current Organic Synthesis
JF - Current Organic Synthesis
SN - 1570-1794
IS - 1
ER -