An acyliminium ion approach towards the synthesis of β-substituted 3,4-dihydroisoquinolone propionates

Article abstract of DOI:10.1016/S0040-4039(97)01285-9

A variety of α-methoxy amides were prepared either by selective reduction of the exocyclic carbonyl of a 2-acyl-3,4-dihydroisoquinolone and subsequent trapping of the resultant α-hydroxy amide with acidic methanol or by reacting the sodium salt of 3,4-dihydroisoquinolone with a functionalized α-chloro ether. These intermediates were reacted with 1-tert-butoxy-1-tert-butyldimethylsiloxy ethene in the presence of BF₃·Et₂O providing access to β-substituted isoquinolone propionates in good yield.