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. Author manuscript; available in PMC: 2014 Oct 2.
Published in final edited form as: Synthesis (Stuttg). 2014 May 1;46(9):1261–1269. doi: 10.1055/s-0033-1340826

Table 2.

Scope of the Asymmetric Synthesis of the Dihydropyran Derivates 4 via a One-Pot Domino Michael–Hemiacetalization and Dehydration Reaction

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4a R1 R2 R3 Yield (%)b de (%)c (trans) ee (%)d,e
4a Ph Me OMe 80 71 95 (71)
4b Ph Me OEt 85 64 88 (73)
4c Ph Ph OEt 81 98 99 (99)
4d Ph Me Me 77 87 92 (99)
4e 4-MeC6H4 Me OMe 81 45 88 (89)
4f 3-BrC6H4 Me OMe 86 76 88 (78)
4g 2-thienyl Me OMe 82 26 90 (94)
4h 3,4-(OCH2O)C6H3 Me OMe 81 43 91 (83)
a

All reactions were performed on a 1.0 mmol scale.

b

Yield of isolated product.

c

Determined by HPLC analysis.

d

Determined by HPLC analysis on a chiral stationary phase.

e

The enantiomeric excess of the minor cis-diastereomer is given in parentheses.