M. Álvarez-mon, J. P. Pivel, J. Quintana, F. Estévez, and J. Bermejo, J. Med. Chem, pp.45-2358, 2002.

T. Esumi, D. Hojyo, H. Zhai, Y. Fukuyama, T. Lett et al., J. Asian Nat. Prod. Res. Org. Lett. ACS Chem. Biol. Green Chem, issue.11 281 11 89, p.670, 1873.

S. Hazra, B. L. Hajra, . Feringab-)-n, A. Kaplaneris, G. N. Bisticha et al., For some selected examples, see: (a) E. Moret and M. Schlosser, Chem. Rev. Green Chem. ChemCatChem Tetrahedron Lett. Tetrahedron: Asymmetry, vol.117, issue.10 11, 1984.

S. H. Yu, M. J. Ferguson, R. Mcdonald, D. G. Hall, V. Mamane et al., J. Am. Chem. Soc. Tetrahedron J. Org. Chem. J. Comb. Chem. Eur. J. Org. Chem. J. Org. Chem. Tetrahedron Lett, vol.63, issue.8, pp.59-365, 1994.

R. W. Schlapbach and . Hoffmann, Eur. J. Org. Chem, p.323, 2001.

M. Yamamoto, N. Takahashi, F. Miyaura-carreaux, B. Possémé, A. Carboni et al., Synlett J. Org. Chem. Chem. ? Eur. J. J. Org. Chem. Chem. ? Eur. J. Org. Lett, vol.128, issue.20, pp.15-2712, 2002.

S. Macé, P. Touchet, F. Andres, V. Cossio, F. Dorcel et al., Angew. Chem., Int. Ed, pp.55-1025, 2016.

, 14 For a review, see, 13 For a recent review about the enecarbamate chemistry, p.1295, 2011.

, 15 At no moment the transient allyl cyanate was detected by 1 H NMR

, 17 This outcome is in complete agreement with those observed in the synthesis of seven-membered ring using a similar strategy, see: ref, 16 This transformation was also described using H 2 SO 4 in, p.772, 2002.

, electron donating group at the 4-position of the aromatic ring favored the elimination of the hydroxyl functional group in the acyclic enecarbamate intermediate 8, thus forming a potential benzylic carbocation with loss of diastereoselectivity. For an example described in the literature, see, 18 Under acidic conditions For the compound 6b, the enantiomeric excess (97%) was determined by GC for the starting (R)-but-3-yn-2-ol, 2017.

C. Jiang, S. Fu, and . Ma, 20 For syntheses of, pp.137-13066, 2010.

F. Schleth, T. Vogler, K. Harms, and A. Studer, 21 For some recent syntheses of (+)-trans-cognac lactone, see: (a), Chem. ? Eur. J. Tetrahedron: Asymmetry, vol.10, issue.23, p.240, 2004.

M. Vieira, A. Kijjoa, A. M. Silva, I. Mondranondra, and W. Herz, Phytochemistry, pp.48-1079, 1998.

M. S. Nascimento, F. Pedro, M. Cerqueira, L. M. Bastos, A. Vieira et al., Pharm. Biol, pp.42-449, 2004.

G. Li, C. Lee, M. Woo, S. Lee, H. Chang et al., 24 For other biological activities in which (?)-galbacin was tested, pp.20-4128, 1147.