Highly facile and stereoselective intramolecular [2 +2]photocycloadditions of bis(alkenoyl)ketenedithioacetals.
The conformational change induced by the introduction of a ketenedithioacetal moiety at C-4 of 1,7-substituted-1,6-heptadiene-3,5-diones results in favorable spatial relationships between the alkenoyl groups to effect efficient intramolecular cycloadditions: irradiation of bis(alkenoyl)ketenedithioacetals in solution leads to facile and stereospecific intramolecular [2 + 2] photocycloadditions resulting in the formation of substituted bicyclo[3.2.0]heptane-2,4-diones, the observed conformational rigidity of which is attributed to the push-pull character of the ketenedithioacetal group.
School of Chemical Sciences, Mahatma Gandhi University, Kottayam, Kerala, India 686 560.
Bubbly K
BK
Joseph
Babu
B
Verghese
C
C
Sudarsanakumar
S
S
Deepa
Dhanya
D
Viswam
Prakash
P
Chandran
C V
CV
Asokan