Michaelis-Arbusov rearrangement

A Michaelis-Arbusov rearrangement followed by a Wittig-Horner reaction is involved in preparation of the distyrylbenzene derivative 11.37, as shown in Scheme 11.15. Precautions must be taken in the first stage to minimise formation of the carcinogenic by-product bis(chloromethyl) ether 11.16. The stilbene bis-ester 11.38 can be made by a similar procedure, or alternatively by the reaction of ethyl acrylate with 4,4 -dibromostilbene in the presence of a palladium-based catalyst (Scheme 11.16), a synthesis that yields the required trans form of the brightener. 

A. K. Bhattacharya u. G. Thyagarajan, The Michaelis Arbusov Rearrangement, Chem. Rev. 81, 415 (1980). A.N. Pudovik u. M.G. Zimin, Addition Reactions of partially-esterified Phosphorus Acids. Rearrangements of a-Hydroxyalkyl Phosphorus Esters and their a-Mercapto- and a-Amino-Analoges, Pure Appl. Chem. 52,989... 

Scheme 7). Attempts at a similar Michaelis-Arbusov reaction using the butynyl chloride (55) unexpectedly gave 2-amino-6-chloro- -9-ethylpurine (56) as shown in Scheme 8. The photo-Arbusov rearrangement has been used as the key step in the syntiiesis of a series of acyclic... 

---