. 2016 Feb 17;7(6):3649–3657. doi: 10.1039/c6sc00185h

Table 1. Optimization of the organocatalytic annulation of oxadendralenic dienal 1a with 2a followed by the one-pot inverse-electron demand hetero-Diels–Alder reaction of intermediate 3a and vinyl ethers 4a and b to form tetrahydroisochromenes 5a and b ^a .

^aExperiments performed on a 0.1 mmol scale. See the ESI for details.

^bYields were determined using 1,3,5-tris(trifluoromethyl)benzene as an internal standard unless otherwise noted.

^cIsolated yield determined after FC.

^dDetermined using ¹H NMR analysis of the crude mixture, see dr of the isolated compound in brackets.

^eDetermined using chiral stationary phase UPC².

^fCo-catalyst and dienophile were added after 1.5 h of reaction time.

^gAll reactants were added simultaneously.

^hThe reaction yielded a complex mixture of unidentified products.

Table 1. Optimization of the organocatalytic annulation of oxadendralenic dienal 1a with 2a followed by the one-pot inverse-electron demand hetero-Diels–Alder reaction of intermediate 3a and vinyl ethers 4a and b to form tetrahydroisochromenes 5a and b a .