... The actual ratio of isomers and the factors controlling their formation are currently under study and will be published in due course. Full Text via CrossRef. 7; All new compounds gave satisfactory analytical and/or spectral data. 8; TV Lee, KA Richardson; Tetrahedron Letters, 26 (1985), p. 3629. 9; G. Majetich, J. Defauw, K. Hull, T. Shawe; Tetrahedron Letters, 26 (1985), p. 4711 and references therein. ...