<A> convenient synthesis of 2-methoxy-1-naphthyl sulfoxides in high enanatiomeric purity. A new asymmetric synthesis of 1-benzyl-1,2,3,4-tetrahydroisoquinolines

Abstract :

The synthesis of diastereomerically pure (-)-(S) menthly 2-methoxy-1-naphthalenesulfinate (5) is reported. The reaction of (5) with methy lmagnesium iodode or benzylmagnesium chloride gives (+)-(R) methyl and (+)-(R) benzyl 2-methoxy-l-naphthyl sulfoxied, (7) and (8) respectively, in high enantiomeric purity (98,ee). Lithiated (8) undergoes addition to 6,7 -dimethoxy-3,4-dihydroisoquinoline N-oxide (2) to give a l-benzyl-1,2,3,4-tetrahydroisquinoline derivative (9) with high product diastereoselection (d.r.96:4). The stereochemistry of (9) was determined by a single crystal X-ray structure determination.

Hajipour, A. R.,Pyne, Stephen G.,Prabakaran, K

convenient synthesis of 2-methoxy-1-naphthyl sulfoxides in high enanatiomeric purity. A new asymmetric synthesis of 1-benzyl-1,2,3,4-tetrahydroisoquinolines