title: Chemical aspects of propranolol metabolism: 1,1-diethoxy-3-(1-naphthoxy)-2-propanol and related ring-closure products cis- and trans-4-ethoxy-3-hydroxy-3,4-dihydro-2H-naphtho[1,2-b]pyran.
abstract: 1,1-Diethoxy-3-(1-naphthoxy)-2-propanol (V), the diethyl acetal of an important aldehyde intermediate in the metabolic N-deal-kylation of propranolol, was prepared from compound X, the product of the reaction of the lithium salt of methyl methylsulfinylmethyl sulfide with 2-(1-naphthoxy)-acetaldehyde. Compound X, as a mixture of three diastereomeric alpha-hydroxydithioacetal derivatives, when treated with ethyl orthoformate afforded the desired acetal V as well as two ring-closure products, the dihydronaphtho[1,2-b]pyrans VI and VII. Compounds VI and VII were characterized on the basis of mass spectral and 1H- and 13C-NMR data. The stereochemistry of these compounds was assigned on the basis of the 300-MHz 1H-NMR spectra of their acetate esters (XI and XII).
mesh_terms: D001711:Biotransformation; D055598:Chemical Phenomena; D002621:Chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D011433:Propranolol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism*; D011714:Pyrans / Q000138:chemical synthesis* / Q000378:metabolism; D013237:Stereoisomerism
chemical_list: C039132:4-ethoxy-3-hydroxy-3,4-dihydro-2H-naphtho(1,2-b)pyran; D011714:Pyrans; C039131:1,1-diethoxy-3-(1-naphthoxy)-2-propanol; D011433:Propranolol