“…58c Finally, as mentioned before for few special cases, the cyclocondensation of the 4-hydroxy-1-alkenyl carbamates 71 with aldehydes or ketones generally provides diastereomerically pure tetrasubstituted tetrahydrofurans (see Scheme 14). 41,42,45 Simpler vinyl carbamates 80 are converted into lithium enolates 81 59 or silyl enol ethers 82, 60 or to vinyl triflates 83. 60 The 2-alkenyl carbamates have been applied to completed or attempted total syntheses of natural compounds by P. J. Kocienski, M. Julia, J. Ardisson, A. Pancrazi, Y. Férézou, I. E. Markó et al, and others.…”