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A mild, diastereoselective construction of cyclic and spirocyclic ketals employing a tandem photoisomerization/cyclization tactic.

ABSTRACT: The cyclization of trans-?-hydroxy enones to cyclic mixed ketals routinely requires superstoichiometric strong acid. By operating under a photoisomerization regime, the cyclization of trans-?-hydroxy enones proceeds under catalytic Brønsted acid to provide cyclic ketals or unsaturated spiroketals in a highly diastereoselective fashion. A one-pot, two-step protocol was thus developed to provide cyclic methoxy ketals with a free ?-hydroxy group for future functionalization.

SUBMITTER: Li B

PROVIDER: S-EPMC4295796 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature

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A mild, diastereoselective construction of cyclic and spirocyclic ketals employing a tandem photoisomerization/cyclization tactic.

Li Bo B Williams Brett D BD Smith Amos B AB

Organic letters 20141209 1

The cyclization of trans-δ-hydroxy enones to cyclic mixed ketals routinely requires superstoichiometric strong acid. By operating under a photoisomerization regime, the cyclization of trans-δ-hydroxy enones proceeds under catalytic Brønsted acid to provide cyclic ketals or unsaturated spiroketals in a highly diastereoselective fashion. A one-pot, two-step protocol was thus developed to provide cyclic methoxy ketals with a free β-hydroxy group for future functionalization. ...[more]

PMID: 25489978

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