60424-17-1Relevant articles and documents
Photochemical Rearrangement of α-Chloro-Propiophenones to α-Arylpropanoic Acids: Studies on Chirality Transfer and Synthesis of (S)-(+)-Ibuprofen and (S)-(+)-Ketoprofen
Sonawane, Harikisan,Bellur, Nanjundiah S.,Kulkarni, Dilip G.,Ayyangar, Nagaraj R.
, p. 1243 - 1260 (2007/10/02)
A new single-step efficient photochemical approach for α-arylpropanoic acids (4) from α-chloro-propiophenones (5) is described.It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent.The mode of the rearrangement is probed by the study of the photobehaviour of a set of optically active α-chloro-propiophenones.The results suggest that the nature of the carbonyl triplets (n, ?*/ ?, ?*) plays an important role in the chirality transfer.This method finds application in the synthesis of optically active ibuprofen (4e) and ketoprofen (26), though in moderate optical yields.
A UNIQUE 1,2-SHIFT SELECTIVITY IN 2-HYDROXYPROPIOPHENONE DIMETHYLACETALS: GENERATION OF NEW METHODOLOGIES FOR METHYL-2-ARYLPROPANOATES AND 1,2-CARBONYL TRANSPOSITION
Sonawane, H. R.,Nanjundiah, B. S.,Kulkarni, D. G.,Ahuja, Jaimala R.
, p. 7319 - 7324 (2007/10/02)
α-Hydroxydimethylacetals I have been shown to undergo two different rearrangements involving highly selective 1,2-shifts under mild conditions.When treated with Ph3P/CCl4 in the presence of pyridine, I were cleanly transformed via 1,2-aryl shifts into methyl 2-arylpropanoates, an important class of antiinflammatory agents; a pronounced substituent effect has been observed in this rearrangement. On the other hand, treatment of I with catalytic amount of Ph3P/I2 in benzene furnished α-methoxy-α-aryl propan-2-ones in excellent yields and culminated in the development of a new methodology for 1,2-carbonyl transposition.
