A Model Study Directed Towards a Practical Enantioselective Total Synthesis of (-)-Morphine

A Comparison of Intrazeolite and Solution Singlet Oxygen Ene Reactions of Allylic Alcohols

“…(9) 1 H NMR (CDCl 3 ) δ 1.25 (d, J = 8.0 Hz, 3H), 1.60 (d, J = 6.7 Hz, 3H)*, 1.63 (s, 3H)*, 4.21 (q, J = 6.4 Hz, 1H), 5.49 (dqq, J = 1.1, 1.1, 6.6 Hz, 1H) *some unresolved long‐range coupling. S*S*‐3‐hydroperoxy‐3‐methyl‐4‐penten‐2‐ol ( 11 ). 1 H NMR (CDCl 3 ) δ 1.14 (d, J = 6.5 Hz, 3H), 1.28 (s, 3H), 4.02 (q, J = 6.5 Hz, 1H), region between 5.32 and 5.4 severe overlap between 11 and 12 , 5.92 (dd, J = 11, 17.7 Hz, 1H), 8.27 (bs, 1H).…”

“…The allylic hydroperoxides were identified by reduction with triphenylphosphine to the diols followed by comparison to published proton and carbon NMR of these compounds. cis ‐3‐methylene‐1,2‐cyclohexandiol (16‐OH) , (10) trans ‐3‐methylene‐1,2‐cyclohexandiol (16‐OH) (10), cis ‐3‐methyl‐3‐cyclohexen‐1,2‐diol (18‐OH) (11), 3‐methyl‐2,3‐epoxy‐cyclohexanone ( 21 ) (12). Spectral data for the trans ‐1,2‐diol, trans ‐3‐methyl‐3‐cyclohexen‐1,2‐diol (19‐OH) is not available but it is tentatively assigned on the basis of comparison of 13 C NMR chemical shifts in the reaction mixture and comparison with those published for 18‐OH (11).…”

Asymmetric synthesis of a model compound for the cyclohexenone core of ambuic acid

“…16 Available online at www.sciencedirect.com Several reagents were assayed for the introduction of the leaving group on carbon 3 (Table 1).…”

ChemInform Abstract: Short Chemoenzymatic Total Synthesis of ent‐Hydromorphone: An Oxidative Dearomatization/Intramolecular [4 + 2] Cycloaddition/Amination Sequence.

“…[3] Two model studies utilizing an intramolecular Diels-Alder reaction to construct ring B, leading to morphinan substructures, have been reported by us [4,5] and by Rodrigo and co-workers. [3] Two model studies utilizing an intramolecular Diels-Alder reaction to construct ring B, leading to morphinan substructures, have been reported by us [4,5] and by Rodrigo and co-workers.…”

“…The functionalities at C16 and C9 are appropriate for the incipient closure of the ethylamino bridge in 3 (or its aromatized equivalent). Deprotection and oxidation will lead directly to ent-hydromorphone (4).…”