... 3. (b); A. García, L. Castedo, D. Domínguez; Synlett (1993), pp. 271–272. ... 4. (c); VL Ponzo, T. Kaufman; Tetrahedron Lett., 36 (1995), pp. 9105–9108. ... in complete agreement with those previously published, see Rahman, A.-U; Malik, S.; Zaman, K. J. Nat. Prod., 1992, 55, 676–678. 10. T. Tsunoda, Y. Yamamiya, Y. Kawamura, S. Itô; Tetrahedron Lett., 36 (1995), pp. 2529–2533. ...